Take a look at only SOME of the information out there about how Craigslist is agreeing to cooperate with law enforcement to aid them in prosecuting criminals, of which prostitution IS ILLEGAL. Now, look at the fact they even have a full time 'law enforcement liason' officer. Further, they cooperate with law enforcement to make sure that "terrorists" are operating through their website.
That said, now take a look at how Craigslist is donating money to:
Now, take a look at who Craigslist donates money to: