The ECI leaks mention that the FBI &quot;compels&quot; U.S. firms to &quot;SIGINT-enable&quot; their stuff for FISA purposes. So, they must have <i>some</i> authority over at least some U.S. companies. If it&#x27;s classified, they also can (and have) use secrecy orders.<p>Then, they pay them too. Many companies, esp govt contractors, were more than happy to help for tens of millions.