I used to meet folks off CL (circa 2005). Either I posted an ad or answered ads in "strictly platonic", "women seeking men" or "men seeking women". I was depressed and seeking something. I started to notice it was the same people posting ads and answering, repeatedly. Maybe they hadn't found a victim yet(victim in any sense of the word). A reporter on WABC radio was murdered after posting an ad for rough sex on craigslist (I'm assuming under "casual encounters"). The teen who answered his ad had a MySpace page that showcased his love of knifes (he stabbed the reporter 50 times) and sadomasochist view and lifestyle.
When I used CL, I googled people all the time. That's just my need to know what's what and who's who and how shit's supposed to go down. Any emails from anonymous addresses like "email@example.com" or "firstname.lastname@example.org" got no response. After the 3rd or 4th time of getting an email, it was an automatic delete. The circumstances of the reporter's murder probably surprised those close to him who had no clue of his "other" life. The internet makes it easy to hide behind a computer screen. The internet also puts everything out there; just takes a little digging sometimes. I always do my research.