Twitter provides material support to ISIS, lawsuit alleges

A US woman whose husband was slain in Jordan while serving as a private contractor is suing Twitter, alleging that the micro-blogging company is a "tool for spreading extremist propaganda" that led to her husband's death at the hands of a terrorist last year.
Enlarge / Contractor Lloyd "Carl" Fields was shot and killed by a terrorist in Jordan last year.

The federal suit (PDF) was filed Wednesday against San Francisco-based Twitter. It claims the service is in breach of the Anti-Terrorism Act, that Twitter "purposefully, knowingly or with willful blindness" provided "material support to the preparation and carrying out of acts of international terrorism, including the attack in which Lloyd Fields Jr. was killed."
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Twitter said the lawsuit is meritless. Taking a page from Google's PR tactics, the company said it would only provide a response if Ars promised to attribute it to a "Twitter spokesperson" and not to any named Twitter employee.
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Twitter, meanwhile, is likely immune from liability under Section 230 of the Communications Decency Act.

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I would imagine twitter doesn't care what is on the site as long as it gets people participating. Fame and fortune.

IIRC, they have taken down posts before if there is enough heat. The suit seems like something that won't go very far.

Section 230 of the Communications Decency Act

Section 230 says that "No provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider" (47 U.S.C. § 230). In other words, online intermediaries that host or republish speech are protected against a range of laws that might otherwise be used to hold them legally responsible for what others say and do.