As everyone else has said, just be careful and pay attention to your insticts. I mostly had very good experiences but did go out on two dates with someone later convicted of date rape (spiking his dates' drinks). He did not do this to me (we were out in public and, both times, people I knew were in the bar and around us at all times) but he did this to several women who left their drinks to use the restroom...so, even with non-online dating or just going out in general, always guard your drink. I hate to sound paranoid but think it's just good practice these days.