According to CNN’s sources, Manafort was subject to FISA surveillance in 2014 due to his dealings in Ukraine. After Russian ties to the campaign surfaced in 2016, another warrant was granted to the FBI.
Assuming the CNN reporting is accurate, this represents a serious leak of national security information coming from within the government. There are few categories of people who would have knowledge of these warrants. These could realistically only be government investigators or people close to Congressional oversight committees. Manafort’s counsel wouldn’t know about the wiretaps unless he is indicted, which hasn’t occurred yet.
The Wall Street Journal also reported on September 15th that Mueller had apparently obtained data from Facebook on Russian ad buys via a warrant. The existence of warrants requiring probable cause shows that the investigation is gaining steam. A judge would have to agree that evidence of a crime likely exists in a places like Manafort’s home, or Facebook servers.
