A declassified list of U.S. officials who received information in response to “unmasking” requests has given allies of President Trump fresh ammunition to question the actions of Obama-era ambassadors.

Rep. Devin Nunes, the top Republican on the House Intelligence Committee, said the National Security Agency memo, which focused on spy intercepts of conversations then-incoming national security adviser Michael Flynn had with foreigners from the 2016 election to Trump’s inauguration, is “just the tip of the iceberg.”