You know, for all of the surveillance the FBI owns, their upper echelon seem completely oblivious to the purpose of Trump's tweet.
They are trying to steer the conversation toward the rank-and-file Agents, the Special Agents, etc. The men and women who are the boots-on-the-ground, and who, most likely, do their job with integrity.
Trump, however, isn't calling out these hard working men and women. He is calling out the upper echelon. The ones who have been bought and sold, who have sacrificed their honor and integrity for money or political points with certain politicians. The very same ones who are willing to throw their entire department under the bus if they think they can "get ahead" for it.
Time will tell if there is a house cleaning. So far, his swamp draining business seems to have been a non-starter. Kind of like any business Cuomo tries to build in New York (other than the business of corruption).