• by Wendy Davis , Staff Writer @wendyndavis, March 6, 2009

It's safe to say that the world's oldest profession would still exist even if Craigslist didn't. Yet Chicago sheriff Thomas Dart seems to think Craigslist plays a crucial role in enabling prostitution. This week, he filed an attention-grabbing lawsuit against the site, accusing it of creating a public nuisance by facilitating prostitution via erotic services ads.

It's not clear what Dart hopes to achieve with this puzzling lawsuit, but his goal couldn't be to make law enforcement's job any easier. Currently, it can't be all that difficult for the Chicago vice squad to find suspects -- which apparently requires only the ability to navigate to Craigslist and send out emails.

What's more, the case doesn't have much chance of surviving a motion to dismiss on the ground that federal law immunizes Craigslist from suits based on user-submitted material. Perhaps the lawsuit would have stood a better chance had it been filed by officials in another city, but federal courts in Chicago have already ruled for the site on a very similar issue. When Craigslist was sued for allowing discriminatory housing ads, the courts threw out the case because the site was protected by the federal Communications Decency Act.

The courts aren't likely to decide this case differently -- nor should they. The ads on Craigslist might make prostitution more visible, but that's the nature of the Web: It makes all sorts of information more accessible. If Dart thinks that people are soliciting crimes online, he can legitimately use that data to make arrests, but it makes no sense to ask the courts to choke off that flow of information.