Zeran was one of the first cases to interpret CDA 230. The decision held that AOL was not liable for a false advertisement placed on an AOL bulletin board, which directed users to call plaintiff and which resulted in him facing significant harassment.
Congress recognized the threat that tort-based lawsuits pose to freedom of speech in the new and burgeoning Internet medium. The imposition of tort liability on service providers for the communications of others represented, for Congress, simply another form of intrusive government regulation of speech.
Because service providers would be subject to liability only for the publication of information, and not for its removal, they would have a natural incentive simply to remove messages upon notification, whether the contents were defamatory or not. Thus, like strict liability, liability upon notice has a chilling effect on the freedom of Internet speech.
Congress made a policy choice ... not to deter harmful online speech through the separate route of imposing tort liability on companies that serve as intermediaries for other parties' potentially injurious messages ... The specter of tort liability in an area of such prolific speech would have an obvious chilling effect. It would be impossible for service providers to screen each of their millions of postings for possible problems. Faced with potential liability for each message republished by their services, interactive computer service providers might choose to severely restrict the number and type of messages posted. Congress considered the weight of the speech interests implicated and chose to immunize service providers to avoid any such restrictive effect.