The FBI has files from a phone-monitoring company whose notorious software was on iPhones, Android phones, Nokias and BlackBerries. But since the files are being used "for law enforcement purposes," the feds won't talk about their contents. So you can't know what secrets the feds have gleaned from your phone, because that's a secret.
The Freedom of Information Act specialists at MuckRock recently asked the FBI for "manuals, documents or other written guidance used to access or analyze data gathered by programs developed or deployed by Carrier IQ," with "Carrier IQ" being that smartphone software that logs and often re-transmits web traffic, button taps, keystrokes, text message traffic, phone traffic, and GPS locations. It's installed on wide range of phones.
The FBI wouldn't give anything to MuckRock except for this very informative brush off: "I have determined that the records responsive to your request are law enforcement records; that there is a pending or prospective law enforcement proceeding relevant to these responsive records; and that the release of the information contained in these responsive records could reasonable be expected to interfere with enforcement proceedings." In other words, the FBI can't say right now if it's using bugs in people's smartphones to put people in prison, because it's busy using bug data to try and put people in prison. A denial that creepy makes you wonder how terrifying an affirmative response would sound.