A newly-released document on Apple's website outlines the company's policies when it comes to sharing the personal information of iOS users with U.S. law enforcement.

According to the whitepaper, the company can help lawmen get their hands on a significant amount of information you share through iCloud, including your e-mail, iWork documents, calendars, and so on--provided, of course, that they come looking for it with a valid warrant.

Perhaps a bit more worryingly, the folks from Cupertino can also help a law enforcement agency to extract certain information from an iPhone or iPad, even if the device is protected by a passcode lock.

Luckily, this kind of operation can only coerce a relatively small amount information from an iOS device, and only from Apple's own apps. This includes data, like call history and SMS messages, that law enforcement could more easily obtain directly from a cell provider, but can also extend to your photos, movies, contacts, bookmarks, and device backups (it's unclear whether the latter are encrypted or not).

Not all bad news

Now for the good stuff: First of all, Apple can't use Find My iPhone to track you unless you turn it on first, and even then it only keeps track of a relatively restricted set of data. This means that the company will respect your privacy if you decide to keep Find My iPhone off, and that it will be able to help Search and Rescue find you in an emergency.

It also looks as though Apple is capable of holding to some of the logs from its lost-device service. Although GPS information is not on record, the company will be able to tell law enforcement if Find My iPhone was used to wipe out an iPhone or iPad remotely--an important bit of information for a prosecutor who is looking to establish whether a suspect attempted to wipe out potentially incriminating data after it had entered into evidence.

Finally, the whitepaper states quite unequivocally that Apple cannot provide access to either iMessage or FaceTime communications, which are encrypted end-to-end to preserve their privacy. If true, this bit of information is, indeed, very big news: It means that FaceTime calls and iMessage chats are, in fact, more secure than their traditional phone and SMS counterparts, which travel in the clear and can be intercepted with a wiretap warrant.