Interesting interview with Mark Levin who was the person who arguably brought this to the public's attention via his radio show.
He quotes public newspaper sources including the Guardian and Washington Post as sources for the two FISA applications. The first one was rejected and the second, more focussed, accepted.
I think he's right that this needs a full investigation. Until that is done, I don't think we can trust the media, Left or Right, to give us unbiased reporting.
https://www.youtube.com/watch?v=q2eu-B5ZNPs