Constraints created when National Security Agency leaker Edward Snowden spilled U.S. secrets add new risk to the agency’s work when the Islamic State of Iraq and Syria and other threats are making the world more dangerous, intelligence community leaders say.

Director of National Intelligence James Clapper acknowledged that Snowden’s revelations about the NSA’s massive data-collection programs had led to a loss of information, damaged relationships with key allies and “conscious decisions to stop collecting on some specific targets.”