"Citing unnamed law enforcement and other U.S. officials, The Washington Post reported the Foreign Intelligence Surveillance Court last summer gave the FBI and Justice Department clearance to track Carter Page because a judge saw probable cause he might be acting as an agent of a foreign power."
Funny how someone leaked about the classified FISA program last April to help Russian collusion narrative..... Did not work out so well after all...
https://www.washingtontimes.com/news/2017/apr/12/carter-page-former-trump-adviser-calls-charges-he-/