President Trump reached a new low on Wednesday when one of his own staffers became the target of one of his Twitter tirades. On Wednesday morning, Trump publicly criticized the manner in which Attorney General Jeff Sessions is choosing to carry out a federal investigation.

Sessions reportedly recruited Inspector General Michael Horowitz, who was sworn in under the Obama administration, to look into alleged surveillance abuse by the Foreign Intelligence Surveillance Act.

“Why is A.G. Sessions asking the Inspector General to investigate massive FISA abuse,” Trump wrote of the probe into the government agency which monitors communication among foreign intelligence agents. “Will take forever, has no prosecutorial power and already late with reports on Comey, etc. Isn’t the IG an Obama guy? Why not use Justice Department lawyers? Disgraceful.”