In this day and age, it's important to manage your online presence. Generally speaking, the first thing I do after meeting a potential date is search for her name online. I know girls do the same thing to me, and I think it's perfectly natural. Cyberstalking is not a replacement for actually getting to know someone, but it is a good way to weed out felons or anyone who did "art films" in college for extra money.
There are a few things you can do to scrub your online reputation. You have to think of it like you're applying for a job and trying to look as squeaky clean as possible.
An important part of the modern vetting process is checking out a potential match's social-media presence. So if you're serious about finding love, it might be a good idea to take any questionable pictures off your Facebook page. No one wants to date the guy who passed out and got a mustache drawn on himself with a Sharpie. And no one wants to date a woman who takes pictures of herself in the bathroom mirror with a camera phone, wearing a bikini and making the duck face. (Although those two should definitely hook up.)
Also, if you're linking politically controversial news stories or making vague posts, like, "I can't believe it happened again," just to get attention, those might constitute a red flag for your stalker.
There are services like Socioclean.com that crawl through your social sites and tell you if something might be inappropriate. I used the service on my Facebook page, and scored surprisingly low. I didn't think I had anything offensive on my page, but I was downgraded for stuff people had posted on my wall, the captions of a few photos I was tagged in and references to me drinking.
You may ask, "Why would I care if someone I might date finds something on my Facebook inappropriate?" It matters because you don't want your prospective honey to know that you're an alcoholic party animal who can out-keg-stand any frat boy, or that you think our president is a Nazi. That makes you look crazy, and it's important to hide that away.
I have a friend who uses a pseudonym for his Facebook page and pretty much everything else he does online. He can be as nasty as he wants, with no consequences. But I'm not necessarily recommending that approach.
If you want to erase your online presence altogether, there are companies that specialize in getting your name off the grid. The Online Scrub and Reputation.com are both designed for people looking for jobs. They can also take your name off of specific things you find objectionable.
The bottom line is that you should cyberstalk. It's a strange piece of advice to give, but it can really be useful. Alternatively, you should expect to be cyberstalked and prepare yourself. Even if you're not looking to date, it's probably a good idea to try and keep your Facebook and Twitter pages free of dumbassery. I guarantee someone is watching and judging you.