Stealing Your Address Book

It’s not really a secret, per se, but there’s a quiet understanding among many iOS app developers that it is acceptable to send a user’s entire address book, without their permission, to remote servers and then store it for future reference. It’s common practice, and many companies likely have your address book stored in their database. Obviously, there are lots of awesome things apps can do with this data to vastly improve user experience. But it is also a breach of trust and an invasion of privacy.

I did a quick survey of 15 developers of popular iOS apps, and 13 of them told me they have a contacts database with millons of records. One company’s database has Mark Zuckerberg’s cell phone number, Larry Ellison’s home phone number and Bill Gates’ cell phone number. This data is not meant to be public, and people have an expectation of privacy with respect to their contacts.

There are two major questions to ask about this behavior:

First, why does Apple allow iOS apps to access a user’s entire address book, at any time, without permission? Even Android requires that apps ask for explicit permission to access local contacts. On iOS, every other seemingly private local data source, like location and the camera roll, have strong protections; apps can’t even see photos in the Camera Roll unless the user explicitly selects them from the image picker. There is a huge section of the Settings app dedicated to giving people fine control over which apps have access to location information. That Apple provides no protections on the Address Book is, at best, perplexing.

Second, why do app developers, who know of the potential public backlash if this behavior were publicized (that’s why they keep it quiet), continue to upload user address books to their servers? I think this question is easier to answer. Any app is an investment, and, like any investment, there are three outcomes – success, failure, and mediocrity. The only one that matters on a market like the App Store is success, so fledgling app developers do everything they can to increase their chances. Because Apple provides extremely easy access to address book data, the pro – that is, using the data to improve user experience, increase virality and growth, etc. – outweighs the con. To stay on equal footing, larger apps, like Yelp, Facebook, and Foursquare, have to follow along. From a design perspective, it is a concession of user growth at the expense of user trust.

Yesterday, it was revealed that the private social network app Path practices this behavior. People were outraged. Today, CEO Dave Morin apologized on the Path blog:

Through the feedback we’ve received from all of you, we now understand that the way we had designed our ‘Add Friends’ feature was wrong. We are deeply sorry if you were uncomfortable with how our application used your phone contacts.

There was similar outrage last year, when Kik was outed. But, after a while, things calmed down. Kik never conceded. Developers continued to stay quiet. Users forgot about it entirely.

Apple’s Failure

I fully believe this issue is a failure of Apple and a breach of trust by Apple, not by app developers. The expectation of Address Book privacy is obvious; in fact, one person on Hacker News, in response to learning about Path’s use of the data, said, “Apple would never do this to their users.” Because Apple has your trust and yet gives this private information freely to developers, Apple does do this to their users. All of them.

Usually, when I am curious about something Apple has done, I try to understand the design thinking that went into the decision. In this case, I can’t think of a rational reason for why Apple has not placed any protections on Address Book in iOS. It makes no sense. It is a breach of my privacy, and it has allowed every app I’ve installed to steal my address book.

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Addendum: Two more things


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