Remember how Airbnb said it would ask you to agree to a non-discrimination policy if you wanted to host guests? That's now in effect. As of November 1st, hosts must abide by rules forbidding them from discriminating against guests. In the US, they're explicitly barred from discrimination based on factors such as race, nationality, disability, gender identity or sexual orientation. Hosts can label shared living spaces as open solely to same-gender guests (to discourage creeps) and warn disabled guests about accessibility problems, but those are the only major exceptions.