Feds Unhappy About iMessage Encryption

"Apple's iMessage encryption trips up feds' surveillance":

An internal Drug Enforcement Administration document seen by CNET discusses a February 2013 criminal investigation and warns that because of the use of encryption, "it is impossible to intercept iMessages between two Apple devices" even with a court order approved by a federal judge.

The DEA's warning, marked "law enforcement sensitive," is the most detailed example to date of the technological obstacles -- FBI director Robert Mueller has called it the "Going Dark" problem -- that police face when attempting to conduct court-authorized surveillance on non-traditional forms of communication.