Yes. Section 230 of the Communications Decency Act of 1996 grants broad immunity to websites that host objectionable content. Originally, this law was enacted to keep Internet Service Providers (ISPs) like AOL from being held criminally liable for content posted by members.
As the Internet has evolved, however, the law has been interpreted to protect virtually any website or Internet service. The broad immunity afforded by this law is partly responsible for the rise of gossip websites and other havens for anonymous online bullying.