There is no evidence that FBI obtained warrants before the Geek Squad informants searched computers they were repairing. It is believed Geek Squad employees routinely search unallocated space for any illegal content that may be on a device and then alert the FBI after conducting “fishing expeditions” for criminal activity, and this is what the FBI trains them to do.
EFF sought “records about the extent to which [the FBI] directs and trains Best Buy employees to conduct warrantless searches of people’s devices.” As is clear, the government stonewalled EFF and only released documents that were already referred to by news media.
The FBI neither confirmed nor denied whether the agency has “similar relationships with other computer repair facilities or businesses.” The FBI also would not produce any documents that detailed procedures or “training materials” for cultivating informants at computer repair facilities.