The Communications Decency Act of 1996 (CDA) was the United States Congress's first legislative attempt to regulate obscene and indecent material on the Internet. In the 1997 landmark case Reno v. ACLU, the United States Supreme Court unanimously overturned most of the statute due to its restrictions on freedom of speech under the First Amendment to the U.S. Constitution. One non-speech provision of the statute, which exempted the operators of Internet services from liability for their users' actions, survived the Supreme Court's action and was severed from the statute. That provision is now known as Section 230 and remains in effect.
The CDA is the short name of Title V of the Telecommunications Act of 1996, as specified in Section 501 of that statute.