Chicago's sheriff may be the No. 1 source of stupidity in the United States
Prostitution was around long before Craigslist appeared and it's a safe bet prostitution will be around long after Craigslist disappears.
It's unlikely Craigslist has any effect on the level of activity, in this area.
If anything, Craigslist would be a benefit to the sheriff, enabling him to, more easily, identify the "perps".
I suspect the sheriff is either a moron, seeking publicity or, my best guess, the number of posts, on Craigslist, shows what a piss poor job he's doing.
Like the "war on drugs", "war on terrorism", "war in Iraq", "war in Afghanistan" and Viet Nam war, a "war on prostitution" is doomed to failure.
As Anonymous Coward observed: "the best way of doing this is to legalise and regulate like they do in the civilised world"...Canada, for instance. 8-þ
If the sheriff were to devote the time he spends persecuting girls who are, for the most part, just doing what they believe they have to or guys who choose to pay for consensual sex, rather than raping a girl, and making an ass of himself to putting the pimps and those who traffic in girls or involve children, IMNSHO, he'd be earning his salary. As it is, again IMNSHO, he's a waste of the taxpayers' money and an embarrassment to law enforcement, Chicago and the United States...none of which need any more damage to their reputations.