May have found what Q was telling John Solomon to shut up about:

We’ve known that the informants included Professor Stefan Halper, Russian businessman Hank Greenberg, former MI6 agent Christopher Steele and former FBI informer Felix Sater. But Solomon was able to uncover at least four others whose names have not been made public. He said he was asked by US government officials not to reveal their names to “avoid compromising their identities or nexus to intelligence and law enforcement work.”

https://www.redstate.com/elizabeth-vaughn/2018/12/01/the-hills-john-solomon-at-least-6-people-tied-to-fbi-or-western-ics-and-2-russians-tried-to-infiltrate-trump-campaign/