First, the requirement for a warrant to search cell phones incident to arrest has been settled law since June, 2014. Before that there was some doubt, but warrants would have been required for cell phones in essentially all other circumstances based on prior law and court decisions. Comey's complaint is not that encryption will prevent searches without warrant (which are illegal) but that when he obtains a legitimate warrant to search a cell phone he may lack the practical capability to do it due to encryption. It is not clear why cell phone encryption hit his hot button (and the Attorney General's as well), since the argument applies equally to many other types of computing equipment.
Second, it not clear that complaining now makes sense. That horse left the barn more than 20 years ago, not long after PGP became widely available when someone noticed that it could be used for files. Those with a need have been able to use government resistant encryption for quite a while, with a relatively little and declining effort. If they did not do so, and by that became vulnerable to capture for crimes, it is their problem.
Third, law enforcement officials still have the capability to obtain call metadata by a court order and, with a warrant, to tap phones. The additional capability to decrypt stored data probably would be useful in some edge cases, but probably also represents a tiny part of the search warrant universe, which itself is a small part of the criminal investigation universe. As they cannot do anything effective to prevent encryption, they might as well put it behind them and get on with their business as well as they can. When it turns out that they have enough probable cause to obtain a warrant, they also are likely to have the authority of the issuing court to bring a good deal of pressure to bear on the recipient who denies access to search the device.
If I had a conspiratorial bent I might think this was a ploy to confuse us into believing that cell phone data encryption was a new and significant impediment to law enforcement activity. I do not think that, but that the complaining officials, like many in all kinds of organizations, have confused themselves into thinking that obscure corner cases are as important as the ordinary common ones.
Biting the hand that feeds IT
