One of the problems with the speedy emergence and massive popularity of Facebook and other social-networking websites, like Twitter and LinkedIn, is that we haven't really grown into a realistic cultural knowledge of how to use them. With other technologies, even when rapidly deployed, society had a sort of grace period to figure them out -- automobiles took a place that had logically been occupied before by horses and carriages, and there were more than two decades between Carl Benz's 1886 patent on the gas-driven automobile and Henry Ford's 1908 introduction of the Model T, during which the new technology of the automobile could start to settle into a place in the popular mindset.

With the Internet generally, and in particular with sites that enhance the individual's ability to share instantaneously with a global audience, we haven't had the same kind of break-in period. All of the mistakes we make now are not only potentially public for all the world to see (as the Star Wars Kid learned) -- they're also really durable, as well. Once something finds its way onto the Internet, it can quite possibly reside there forever.

Thus when we equip ourselves with tools like Facebook, we're potentially a lot like toddlers in an armory full of loaded weapons. We don't really know the full extent of what we're doing, and the consequences can be permanent. This potentially dangerous situation is made even more hazardous by the fact that social-networking sites are designed to encourage the user to over-share. This is very much by design. The act of adding another person to one's social network on Facebook is called "friending". Whether or not we should even do something like that to the English language, the fact remains: One is programmed to believe that Facebook information is just shared with a bunch of "friends". This psychological programming just enhances some participants' willingness to throw caution to the wind and share too much. But no matter how the language of a social-networking site is framed, it is nearly impossible to ensure that the information one shares there will only go to true friends, and that it won't be deliberately misused by others. Thus, some precautions are in order.

There are many things that should never be shared online, and particularly not in a semi-public space like Facebook. Here are four particular examples:

#1: Never share your full birthdate or place of birth in a social-networking profile. There's a lot of pressure to do this. Facebook recently changed its profile layout, and it leaves a gaping hole for the user to see if he or she hasn't entered a hometown. And there's no doubt that one of the most popular uses of Facebook is to leave a birthday greeting for friends (and, most people should be ready to admit, mere acquaintances). But the problem is that those two facts, long assumed to be the kinds of things that only close friends and family might know, have also long been used by companies and organizations to help positively establish a person's identity. There are innumerable websites, for instance, that still ask "What is your hometown?" or "What was your place of birth?" as a security question. And while it's patently irresponsible for those sites to continue using those as security questions (since it really is absurdly easy to figure out anyone's place of birth), until they stop, it's unwise for anyone to share that information willingly on the Internet. And if there's any factoid used more often than the place of birth to establish a person's identity, it's the date of birth. In some cases, a name and date of birth are all that a person might need to offer to get access to medical records at a doctor's office -- especially by phone. Hometowns should always be omitted from social-networking profiles, and if one can't resist the urge to share his or her birthday, then one should at least leave off the year of birth. Again, it might not be very difficult for a crook to deduce, but there's no reason to make the job easier.

#2: A social-networking profile should not include photos or names of minor children. This prohibition probably sounds needlessly harsh, but it's actually surprisingly vital. First, bridging the notes in rule #1 about security questions, a question that remains much too widely-used in the security field is "What is your mother's maiden name?" Again, that may have been a suitable security question 20 years ago, but it's absolutely not today, when Facebook profiles, e-mail addresses, and old accounts of a million kinds routinely contain a woman's married and unmarried last names. A woman's "maiden name" is no longer any more challenging to figure out than her eye color. And if she leaves a digital footprint behind with her children's names, then she totally renders useless any online security checkpoint that asks the question. The question itself should be thrown out because it's totally obsolete today, but until that happens, there's no need to make crime easier for identity thieves and other crooks.

But there's also a more immediate risk for children, and it is that they become too easy to identify when their parents advertise them on the Internet (which is exactly what happens on a Facebook page, unintentionally or not). There is no reason to make the task easier for potential abductors by sharing names, routines, schedules, and photographs of a whole set of family members via Facebook. One might think, "Well, I only have 100 friends on Facebook, and I'm not worried about any of them." But how certain can a person be that each of those 100 friends are sufficiently security-conscious that they'll never have their accounts hacked?

And then, of course, there's also the concern that a parent should have about his or her child's reputation and good name. As of the latest count, a video entitled "David After the Dentist" had been viewed more than 82 million times on YouTube. It's funny, to be sure. But it's also going to be something for which that child will be known most likely for the rest of his life. Celebrity may be fleeting, but once it's been digitized and placed on the Internet, it's pretty durable as well. Leave the choice in the child's hands whether to put up pictures or videos of him- or herself once they reach adulthood. It's shocking, really, that virtually everyone can agree that youthful fame probably did permanent damage to Michael Jackson, but so many of those same people have no second thoughts about exposing their own children to Internet fame.

#3: No profile should detail a favorite book or movie or song. There are a few errors made here: Either one makes the mistake of sharing just a single favorite of each (which is, following the basic details of a person's birthdate and birthplace, yet another favorite "security" question), or one shares far too many of these items. If there's one thing to be learned from Netflix and its movie-recommendation algorithm, it's that a whole lot of predictive power is attached to whatever a person has strongly liked or disliked in the past. There's nothing particularly wrong with sharing five or ten favorite books or movies, but sharing dozens or scores of them gives away a lot more about one's psychological profile and other behaviors than are necessary to share. Sites like Facebook aren't being operated for the public interest; they're not charities. They make money, and they do that by selling detailed profiles of their users, whether that's as aggregated data, anonymous profile information, or otherwise. No matter how it's sliced up and sold, the data itself has enormous value, and simply giving it away for free -- especially in massive volume -- is a lot like going to work and declining to take a paycheck.

#4: One's immediate location does not need to be shared, ever. Shy of those rare instances (like the moment a commuter snapped a photo of the US Airways flight that landed in the Hudson River) when something truly remarkable has taken place, it's a bad idea to publicly share one's location -- or one's plans to be somewhere at a particular time. Giving away the details on an upcoming two-week vacation is the equivalent of putting a sign in the front lawn saying "We're not home". Posting a snapshot to Twitter of crazy times at a bar might just be telling an unstable ex or a faceless stalker where they can find inebriated prey. Even sharing too many photos of the commute to and from work might be an act that betrays when one's latchkey kids might be home alone.

It's altogether too easy to forget that what we place on the Internet appears on a global stage -- a stage that's not full of just bubblegum and teddy bears. It's a world in which today's supercomputers will very shortly become cheap, affordable tools that could be used by anyone -- with any kind of intent, whether innocent or malicious -- to scrape together the many little breadcrumbs we leave behind on the Internet to build a profile of any one of us that would have made J. Edgar Hoover envious. It is essential that nobody be lulled into a false sense of security about what they share on the Internet. As it's been said about crime, "The crooks only have to get lucky once. The cops have to get lucky every time." As Internet users, we are collectively in the same position as the police -- hoping, almost as much as deliberately trying, to keep our privacy, dignity, and security intact in the face of a world that may have a lot of reason to try to take those things away.

People often wonder why the computers that seemed so fast when they were fresh out of the box turn out to become such slow-moving dullards after a year or two of use. While some slowdown is inevitable, there are some things that people can do to improve computer speed and performance, several of which are just good common-sense elements of a computer maintenance program.

Let's look at the reasons why a computer might be running slowly. First, we need to break down the problems into two categories: The physical and the digital. The home computer itself is, of course, a piece of machinery, and like all machinery, it has moving parts and things that wear out. There's not a lot that can be done for most computers from a physical standpoint -- when things break, they tend to break catastrophically, like a motherboard burning out or a hard drive failing. But when it comes to the speed of a computer, there's a persistent little problem that often goes overlooked by the novice user: Dust. Dust is everywhere and cannot be eliminated unless you live in a clean room. And though it may seem innocuous, dust accumulates inside the computer and builds up around the CPU and around fans. That's a problem, because a computer that can't keep its processing system cool is a computer that works harder than it needs to (physically) to do the job of computing. Hence, tip #1 is simple: Apply a good shot of compressed air to fans and ports to the computer once every few weeks. It may seem like a silly bit of nonsense, but keeping the inside of the computer well-cleaned of dust keeps the CPU cooler, and that helps the computer perform better -- not to mention, if it's a laptop, that it keeps the machine from burning your legs.

Most ordinary computer users shouldn't do a lot more than that to address the physical needs of the computer, so we turn to the digital. The main digital culprit to what slows down most computers is programs that run when they aren't needed. We can break these down into two categories, each with an action step: Programs we deliberately install, and programs we didn't choose to install.

Among programs that we deliberately install, there are a huge number of programs that essentially declare, "Hey, I'm such an important program that you'll need to use me a lot. To make me install faster when you use me, I'm going to create a little preloading routine that makes me start up every time you start your computer." These preloading routines are common -- you'll find them built in to everything from office suites like Microsoft Office and OpenOffice to instant messaging programs and Skype. The problem is that what might make sense for one or two programs doesn't make sense when you have dozens loaded onto your computer at once. Honestly, you just don't need a lot of programs to pre-load themselves every time you use your computer. Sure, you sometimes want Skype to run, but it doesn't really need to pre-load itself every time you hit the power switch. This brings us to tip #2: Shut off the pre-loading feature in any program you don't use every single time you boot up your computer. You can usually disable the pre-loading feature by looking inside the options menus of most programs. For programs where that doesn't work, or to take care of several programs at once, you can follow some simple instructions to manage your startup programs list. One of the worst offenders on this list of self-important programs is Apple's iTunes, which defaults back into your startup menu every time you update the software. It's an obnoxious feature, and the people at Apple should knock it off. There's no reason for iTunes to pre-load every time.

Finally, we have the problem of software that you didn't deliberately install on your own computer. Broadly speaking, we call this stuff malware: It's our umbrella term for viruses, Trojan horses, and spyware -- anything bad (hence the prefix "mal-") that you don't want on your machine. This stuff can seriously hoover up more of your computer processor power than anyone should ever be willing to give away. There are two steps involved in cleaning up the malware on your computer, so we'll break up this third tip into two parts: Tip #3A is to run a complete and comprehensive anti-virus and anti-spyware scan of your computer. We are asked on the WHO Radio Wise Guys program all the time where people can get free antivirus software, and it's available from a number of sources (I think Avast is probably the best among them, at least as of this writing). But if there's one thing you should be willing to pay out-of-pocket to get on your computer, it's good antivirus software. Seriously. Pony up the $30 or $40 it takes for an annual subscription to a professional service like Norton Antivirus or Kaspersky, and get professional-quality antivirus protection. Most of the good (paid) antivirus programs also check for spyware. Yes, the free programs are better than nothing. But the paid stuff is better. Seriously, just pay for it -- just like automobile insurance and health insurance and homeowner's (or renter's) insurance, the cost of antivirus software is just the price you pay for having stuff you want to protect.

Once you've scanned the computer in full and have swept all of the bugs out, it's time to make sure that you don't let them back in again. Hence, we reach tip #3B: Use your administrator account only for installing and upgrading programs, and practice safe Internet browsing. Most people live dangerously by surfing the Internet and reading their e-mail while on an administrator-level access account on their computers. That's dangerous, because the computer assumes that the administrator is authorized to install programs whenever he or she wants. The trouble is, the computer is stupid and doesn't know the difference between you deliberately installing a program and you accidentally downloading a virus (which is, of course, a program). The computer, being stupid, allows you to do either thing without a lot of resistance when you're logged in as an administrator. The way to avoid this is by creating a second profile on your computer and giving it only limited powers -- not including the right to install programs. It's free and easy to create a limited-access account, and that account is where you should stay for 99.9% of your computer use, whether it's watching movies or surfing the Web or checking your e-mail. The limited part of "limited-access" doesn't keep you from doing these things, it just keeps you from installing programs. You can always log into your administrator account if you need to install something new, but -- honestly -- how often do you do that? Once a month? Get into the habit of doing most of your computing from behind the safety wall of a limited-access account. Remember, your computer doesn't know the difference between you and a virus pretending to be you. So if you're logged in with a limited-access account, the computer will just say "No" to installing new stuff -- whether it's you trying to do it, or (more likely) a virus trying to install itself. The limited-access account isn't a complete failsafe insurance policy, but it's probably 95% effective against allowing spyware and viruses onto your computer, all by itself. For additional safety, I recommend that you use an alternative Internet browser (by "alternative", I mean one that isn't the #1 browser, which at present and for about a decade has been Microsoft Internet Explorer). Use Firefox or Opera or Chrome or something else -- just do what you can to avoid using the same browser as the majority of other users. The IE browser itself is OK, but it's also so popular that it's a major target for crooks who write viruses. They know that most people are using IE, so they try to take advantage of its weaknesses. If you don't use it, you'll find yourself less exposed to danger.

These are three simple steps you can take towards faster computing, even on an old machine. Remember, computers don't last forever, so you should always backup your important data (like financial records and photographs), just in case something catastrophic happens to the machine itself. But these tips should generally help keep your computer running at its top available speed.