Bingo! You can, as far as I know, confiscate and search a suspect just based on probable cause, whereas you'd need to have at least a subpoena if not a warrant to get wiretap authorization or phone records.
A recent Supreme Court ruling[0] makes it unlawful for authorities to search confiscated cell phones without a warrant. They could, theoretically, confiscate your phone based on probable cause, but searching it would be a different matter.
[0] http://www.supremecourt.gov/opinions/13pdf/13-132_8l9c.pdf