Congressional critics of government surveillance blasted the NSA and promised additional hearings after the Obama administration on Wednesday declassified documents that show thousands of Americans’ emails had been scooped up.

The unlawful collection, which the documents reflect ended in 2011, confirmed the worst fears of some lawmakers and civil liberties advocates — that the NSA’s ability to monitor foreigners’ Internet conversations had collided with the Constitution, threatened U.S. citizens and will require significant reforms.