Brennan briefed Obama about Hillary's Russian Collusion plot
In fact, the Intelligence Community allegedly referred the allegations about Clinton's Russian Collusion scheme to the FBI for investigation on September 7th, 2016, well before the election.
That's not "Hey, maybe the Trump campaign is colluding with Russia"; it's "Hey, the Clinton campaign is trying to spread false allegations that the Trump campaign is colluding with Russia".
And yet, the FBI already had an investigation open based on those false accusations and continued to pursue it, even well past the election.
If this claim by Brennan and the intel community can be proven, it would seem to put the FBI on the hot seat for knowingly pursuing false allegations against the Trump campaign and then the Trump administration.
UPDATE: Probably also worth noting specifically. When something is "referred to the FBI", the usual context appears to be referring a potentially criminal act for the FBI to investigate. So if Clinton's attempt to falsely link the Trump campaign to Russia is being referred to the FBI, it's not being referred because the FBI should investigate whether Trump is linked to the FBI (as actually happened); what the FBI should be investigating is whether Clinton is trying to frame her political opponent.
UPDATE: Sara Carter has more details.
UPDATE: I was probably wrong about this being a referral to investigate the Clinton campaign. Looks like the CIA referred this to the FBI to investigate Trump, knowing it was a Clinton plot of which the Russians were aware.