Of course that's true for more traditional dating, but it's way easier to hide behind a computer screen and do all sorts of nefarious things. There's no reason to be scared of online dating, and most situations end up just fine, but you should definitely look out for yourself when it comes to meeting up with strangers from the Internet. These tips for online dating chat are a good place to start. And that's precisely why you should save revealing your phone number, address, and even your last name for once you really get to know someone.
Legitimate online daters will understand the reasons for doing this and will be doing the same themselves. In fact, you might even want to take safety precautions a step further by only using generic photos that you took specifically for the dating site.