Here’s a prime example of just how much our smartphones know about us: Apple has filed a patent application for a system that compares the actions of an iPhone user against behavior data gathered during use to prevent thieves, peeping lovers, and others from using the device.

There’s no doubt that such a tool would prove useful. Besides the cost of getting a new phone, perhaps the greatest damage incurred when an iPhone is stolen is the fear of having personal information, from banking data to private messages, compromised by the device’s new owner.

But that doesn’t mean that the implementation of such a system isn’t worrying. Smartphones already contain an extraordinary amount of information about their owners — is knowing that they’re comparing every tap, swipe, and keystroke to a historical database really comforting?

Pando’s Yasha Levine wrote about these ubiquitous snitches and their abilities in February:

In 2010, the Wall Street Journal published an investigation that found smartphones were being hit with an “intrusive effort by online-tracking companies to gather personal data about people in order to flesh out detailed dossiers on them.”

Intrusive or not, surveillance capabilities are built into the very fabric of our smartphones. The intrusive snooping is carried out by Google and Apple as a matter of routine. Google can offer users more protection if the company wanted, but it explicitly chooses not to. Late last year, Google actually turned off an Android feature that gave users slightly more control over app data collection. Google explained that the release of these privacy features was an accident.

Expanding those surveillance capabilities in the name of digital security is going to be a tough sell. What’s the point of protecting information from other people if it requires surrendering more data to a large corporation like Apple? That’s just like trading one intruder for another.

Besides, having even more personal information stored on an iPhone might not offer much in the way of security, at least when Apple’s past security failures are considered. As I wrote when a few hackers took control of some iPhones in Australia to extort money from their owners,

Given Apple’s unwillingness to clearly explain security problems to its customers, its inability to implement basic security features, and, most recently, its incapacity to remember to make sure consumers can download operating system updates by renewing a critical SSL certificate, people might think that Apple’s security tech is as effective as crossed fingers and rabbit feet.

I don’t know about you, but I would prefer for there to be more than rabbit feet and crossed fingers in place to protect information describing the things I do with my smartphone. While it’s unclear that Apple will ever introduce a system like this — tech companies file patents for things they never intend to make all the time — its mere consideration is a tad disconcerting.

[illustration by Brad Jonas]