In the Crossfire Hurricane case, an FBI Lawyer - Kevin Clinesmith doctored an email from the CIA and used the doctored email as fake evidence to secure a FISA warrant. He doctored the email to mean the exact opposite of what the email was communicating. It seems to have been uncritically assumed that this lawyer acted alone and nobody else at the agency was aware of this act. Stories like this seem to suggest that this manner of operation could be fairly routine at the agency.