How the surveillance of Trump team worked
What makes this problematic is that those whose "incidental" conversations were picked up were then illegally "unmasked" by the security services and the transcripts were passed around and in some cases eventually leaked to the media. What this also demonstrates is that the President is not paranoid. This may not have been "wiretapping" in a very technical sense of the word, but does demonstrate how the Obama administration was using incidental contacts as a form of surveillance of a political opponent.
Monitoring described by the chairman of the House Intelligence Committee would have been targeted at foreign officials, not specific members of the Trump transition or Mr. Trump himself.