The Justice Department opened a leak investigation and took aggressive steps to identify the officials who spoke with The Times. Some officials were asked to turn over their cell phones at the White House, sources familiar with the matter told CNN.

Some of the subpoenas — which are court orders compelling a person to testify — were delivered by FBI agents at the reporters’ homes.

The Times publicized the legal threat right away and aggressively fought back, calling the subpoenas a “bad faith effort to harass and intimidate” the news media.

The Justice Department said it was not targeting the reporters; it was pursuing the leakers of classified information.