tbh I would tread with caution, but I wouldn't write it off altogether. I personally don't have experience of internet dating, but I have a friend who met her current dp on an internet dating site and they've been together for around 6 months now. But before he came along she met and was contacted by some very questionable people.
If you're going to be dating people from the net, I would try and do the following:
firstly, I would try and meet the date in person as soon as possible. The internet can be a very deceptive place, and the longer you talk to someone online, the more they can effectively deceive you into believing they're something they're not. It's very very easy to create an internet persona, and you can be hooked before you've even met someone, the longer you talk to someone, the easier it would be for that someone to fool you into thinking they're someone they're not. So i would meet within a couple of weeks at most, of having made the connection.
Secondly, and this is pure common sense stuff, but never give out too much information about your personal circumstances. Never give your address to a man you've never met, and don't give out your home phone number either, give out a mobile number, that way you can switch it off if you don't want to be called by someone you don't want to talk to, and also, it's easy to trace someone if they have a home phone number.
And if you're going to meet someone, make sure you do it in a public place and that someone knows where you are.
I know this sounds like teenage warning type stuff and I don't mean to come across as patronising or lecturing, but I know from first hand experience that people online aren't always what they seem, luckily for me the person I was talking to wasn't in the same country, but I consider myself to be a good judge of character, and I got it totally wrong, I also know of someone who started an on-line relationship with someone who she invited to go and stay with her in the states. He did, (he was from the UK btw), he stayed for two weeks and the day before he was due to leave he raped her and physically asalted her 9 month old DD, breaking her leg. She really thought he was a nice bloke, because he'd led her to believe he was such over the months they'd been talking.
There are some lovely people online, after all we're all on a website now and the vast majority of us don't appear to be freaks, but it's just so much easier to deceive online that it's so much more important to be that much more careful.