An anonymous reader quotes a report from Network World: The Orange County Weekly reports that Best Buy's "Geek Squad" repair technicians routinely search devices brought in for repair for files that could earn them $500 reward as FBI informants. This revelation came out in a court case, United States of America v. Mark A. Rettenmaier. Rettenmaier is a prominent Orange County physician and surgeon who took his laptop to the Mission Viejo Best Buy in November 2011 after he was unable to start it. According to court records, Geek Squad technician John "Trey" Westphal found an image of "a fully nude, white prepubescent female on her hands and knees on a bed, with a brown choker-type collar around her neck." Westphal notified his boss, who was also an FBI informant, who alerted another FBI informant -- as well as the FBI itself. The FBI has pretty much guaranteed the case will be thrown out by its behavior, this illegal search aside. According to Rettenmaier's defense attorney, agents conducted two additional searches of the computer without obtaining necessary warrants, lied to trick a federal magistrate judge into authorizing a search warrant for his home, then tried to cover up their misdeeds by initially hiding records. Plus, the file was found in the unallocated "trash" space, meaning it could only be retrieved by "carving" with sophisticated forensics tools. Carving (or file carving) is defined as searching for files or other kinds of objects based on content, rather than on metadata. It's used to recover old files that have been deleted or damaged. To prove child pornography, you have to prove the possessor knew what he had was indeed child porn. There has been a court case where files found on unallocated space did not constitute knowing possession because it's impossible to determine who put the file there and how, since it's not accessible to the user under normal circumstances.