Civil liberties advocates and a bipartisan group in Congress stepped up pressure on Tuesday against the Obama administration’s secret domestic surveillance programs via a lawsuit and legislation that could shed light on the scope and legality of the government’s snooping.

The American Civil Liberties Union filed suit in New York federal court against the U.S. Justice Department and other federal agencies, challenging the constitutionality of the government’s review of millions of phone call records on Verizon subscribers. ACLU lawyers contend the government’s "dragnet acquisition" is likely to have a chilling effect on speech.