Quote form this article says it all:

"But speaking of stupid, something else occurred that few are mentioning, but may be of more significance than anything. What were these FISA judges thinking who allowed for the surveillance? They actually read the Steele dossier, one would assume. Were they imbeciles or as biased as McCabe, Strzok and the rest of that seedy FBI cabal? Whether they were told that document came from the Clinton campaign or not, it read like an outtake from the back pages of the National Enquirer — and not one of the good issues (John Edwards, etc.). The dossier was ludicrous on its face, yet the supposedly great legal minds of the FISA court accepted it as what appears to be the most important evidence for the case."