Twitter is suing the US government because it wants to disclose information regarding the government's surveillance of its customers.

It alleges the US is violating its First Amendment rights by restricting what it can say about national security requests for user data.

The suit was filed in US District Court for Northern California in San Francisco.

Twitter's legal counsel Ben Lee blogged on his company's site: "Our ability to speak ahs been restricted by laws that prohibit and even criminalize a service provider like us from disclosing the exact number of national security letters and Foreign Intelligence Surveillance Act court orders received."

Twitter had been negotiating a information disclosure arrangement with the Justice Dept. and FBI.