If I'm under criminal suspicion for a crime committed in the U.S., the FBI or local law enforcement agencies need to get a warrant to intercept my communication

If I'm under criminal suspicion for a crime committed in the U.S., the FBI or local law enforcement agencies need to get a warrant to intercept my communications. There is evidence that the FBI also engages in warrantless wiretapping. See http://mitpress.mit.edu/books/privacy-line http://mitpress.mit.edu/books/privacy-line