A DEA report obtained by CNet has revealed that law enforcement has been stumped by communications sent over Apple's encrypted iMessage system. It turns out that encryption is only half the problem, and it's really legislation that keeps iMessages invisible to law enforcement.
Soghoian told SecurityWatch this law, "mandated that industries build in intercept capabilities to their networks." These industries included phone and broadband companies, but not companies like Apple. iMessage is also different from normal text messaging because it both encrypts the message and sends it peer-to-peer between iPhones, without touching a carrier's network.