When you run a roommate-matching service, you need to be careful about what questions you ask, as Roommates.com has just learned the hard way. The Ninth Circuit Court of Appeals recently ruled (PDF) that the service did not qualify for a Safe Harbor under Section 230 of the Communications Decency Act (CDA), bucking the trend of courts finding online entities to be generally immune from their users' actions. The case now goes back to a lower court, where Roommates.com could well be on the hook for violating the Fair Housing Act-all because of a couple questions.

The CDA contains a Safe Harbor which indicates that online service providers are not generally liable for the infringing or illicit content posted by their users, so long as the service providers are simply offering a set of tools. Once they get involved in shaping the content, though, they can lose this protection.

That's what happened to Roommates.com, which was sued by the Fair Housing Councils of San Fernando Valley and San Diego on the grounds that it was helping landlords to discriminate against certain kinds of tenants. Two separate sections of the registration process were brought into question in court: the first involved questions about the user's gender, sexual orientation, and number of children. By asking these questions, was Roommates.com shedding its Section 230 Safe Harbor and getting involved in the creation of content?

The Court said yes. Though it refused to rule on whether Roommates.com actually violated the Fair Housing Act, the Court did find that it lost Section 230 immunity because it required users to enter that information in order to proceed. As Judge Alex Kozinski put it in his opinion, "if it is responsible, in whole or in part, for creating or developing the information, it becomes a content provider and is not entitled to CDA immunity."

In addition to providing users with questions about gender, sexual orientation and number of children, Roommates.com allowed users to search for potential roommates with profiles compatible with their preferences. E-mail notifications sent by Roommates.com with potential matches were also filtered by Roommate.com to exclude incompatible users.

The court held that the combination of Roommates.com questions and prompts along with how Roommates.com categorized and channeled submitted information made Roommates.com responsible, at least in part, for creating or developing the content that formed the basis of the plaintiffs' FHA claim.

According to the court, "by categorizing, channeling and limiting the distribution of users profiles, Roommates.com provides an additional layer of information that it is responsible at least in part for developing." The court also compared Roommates.com to a hypothetical site that provided: "a forum designed to publish sensitive and defamatory information, and suggested the type of information that might be disclosed to best harass and endanger the targets".

The Ninth Circuit remanded the case to the district court for a determination of whether Roommates.com violated the Fair Housing Act.