So held a federal district court in Dart v. Craigslist, Inc. Here’s what plaintiff, the Cook County, Illinois, Sheriff claimed:
Sheriff Dart alleges that, notwithstanding Craigslist’s warnings, users routinely post advertisements in the eroticservices category “openly promis[ing] sex for money.” Based on the samples that he cites in his complaint most of the ads are veiled (sometimes very thinly) using code words.
The court’s reasoning, which seems quite right to me: 47 U.S.C. § 230 generally immunizes Internet service providers from (among other things) being held civilly liable on the grounds that they are “publishers” of material that is supplied by their users. The Seventh Circuit has not read this as broadly as some other courts, but even under the Seventh Circuit’s reading, Craigslist immune because its alleged liability would stem precisely from the fact that it published material provided by its users. “A claim against an online service provider for negligently publishing harmful information created by its users treats the defendant as the ‘publisher’ of that information,” and is therefore preempted by § 230.
The court also considered the Ninth Circuit’s holding in Fair Housing Council v. Roommates.com (discussed here), under which a service provider could be held liable for its own actions in actively inducing people to post illegal content (some paragraph breaks added):
Sheriff Dart insists, on the other hand, that Craigslist plays a more active role than an intermediary or a traditional publisher. He claims that Craigslist causes or induces its users to post unlawful ads — by having an “adult services” category with subsections like “w4m” and by permitting its users to search through the ads “based on their preferences.” “A website operator can be both a service provider and a content provider: If it passively displays content that is created entirely by third parties, then it is only a service provider with respect to that content. But as to content that it creates itself, or is ‘responsible, in whole or in part’ for creating or developing, the website is also a content provider.” Roommates.com. This theory finds some support in Chicago Lawyers [a Seventh Circuit case], which indicated that notwithstanding § 230(c) Craigslist could be held liable for “causing” discriminatory ads if that was in fact what it had done. And we are mindful that whatever the exact parameters of § 230(c)(1) “immunity” are, it is not a “general prohibition of civil liability for web-site operators and other online content hosts.” ... “‘[I]nformation content providers’ may be liable for contributory infringement if their system is designed to help people steal music or other material in copyright.” ... But as the [Seventh Circuit] observed in Chicago Lawyers, “[n]othing in the service craigslist offers induces anyone to post any particular listing.”
We disagree with plaintiff that the “adult services” section is a special case. The phrase “adult,” even in conjunction with “services,” is not unlawful in itself nor does it necessarily call for unlawful content. Cf. Roommates.com (concluding that § 230(c)(1) did not protect a website operator whose roommate-matching service “require[d]” users to answer discriminatory questions from a menu of answers that the defendant supplied). The same is true of the subcategories. Plaintiff is simply wrong when he insists that these terms are all synonyms for illegal sexual services. A woman advertising erotic dancing for male clients (“w4m”) is offering an “adult service,” yet this is not prostitution. It may even be entitled to some limited protection under the First Amendment.
Plaintiff’s argument that Craigslist causes or induces illegal content is further undercut by the fact that Craigslist repeatedly warns users not to post such content. While we accept as true for the purposes of this motion plaintiff’s allegation that users routinely flout Craigslist’s guidelines, it is not because Craigslist has caused them to do so. Or if it has, it is only “in the sense that no one could post [unlawful content] if craigslist did not offer a forum.” Section 230(c)(1) would serve little if any purpose if companies like Craigslist were found liable under state law for “causing” or “inducing” users to post unlawful content in this fashion.
The fact that Craigslist also provides a wordsearch function does not change the analysis. The word-search function is a “neutral tool” that permits users to search for terms that they select in ads created by other users. It does not cause or induce anyone to create, post, or search for illegal content.