Perhaps, and if that is the case they are in bigger trouble.
Trump better have some really good protection against really sophisticated methods of physical incapacitation. Considering the Pizza Party and all the child trafficking busts and all the illegal sabotage in the Bureaus and ...and...and- a large chunk of the Ruling Class stands to be divested of much wealth and time. They have access to some very advanced and subtle tools and Trump does not yet have control of the largest portion of the Executive Branch which is staffed by Leftists and a fair number of Moslems.
I’ve read some speculation that the intercepts actually came from a friendly foreign intelligence service—perhaps upon request. This information was then disseminated widely within the US intelligence community.
With regard to FISA warrants, it is possible that the Obama administration attempted to use the FISA process to launder information initially obtained elsewhere. In legal parlance, this is called parallel construction.