A letter by Senators Ted Cruz, Chuck Grassley, and Mike Lee accused the FBI of conducting a "covert surveillance” targeting congressional staff members. This information came to them from a whistleblower support organization called Empower Oversight which got the information from a FOIA request.
Letter to AG Garland re DOJ-FBI Senate Staff Subpoenas
The FBI subpoenaed private phone and email records from House and Senate staff members who were attempting to investigate the Russia hoax against Trump.
The Senators demanded that AG Garland come forward by Nov. 22 with the names of any other members and staff whose communications were sought or obtained; as well as the DOJ officials who signed off on the subpoenas. They also asked him to provide the evidence that was used to obtain the surveillance. They also want to know which social media and phone companies were subpoenaed for the data.
My other question is why would a judge grant it? If as was the case in the FBI investigation of Trump, the judiciary is just a rubber stamp for a police state then we have even greater issues .