"After the San Bernardino shootings, the FBI seized the iPhone used by shooter Syed Rizwan Farook. The FBI has a warrant to search the phone’s contents, and because it was Farook’s work phone, the FBI also has permission from the shooter’s employer, the San Bernardino County Department of Public Health, to search the device. Legally, the FBI can and should search this phone. That’s not up for debate. If the FBI gets a warrant to search a house and the people who own it say okay, there’s no ambiguity about whether it can search the house.
But if the FBI comes across a safe in that house, the warrant and permission do not mean it can force the company that manufactures the safe to create a special tool for opening its safes, especially a tool that would make other safes completely useless as secure storage. That’s the situation that Apple’s dealing with here."