Over the course of the past week, a firestorm has erupted in the world of iOS apps, thanks to the discovery that Path was uploading data from your iPhone's address book without asking for explicit permission. Upon opening the app and registering, Path automatically uploaded your contact data in order to "find friends" that you might want to connect to. Path has since apologized and updated its app, but the problem exposed by the episode remains.

Stated simply: any iOS app has complete access to a large amount of data stored on your iPhone, including your address book and calendar. Any iOS app can, without asking for your permission, upload all of the information stored in your address book to its servers. From there, the app developer can either use it to help find your friends, store it in perpetuity, or do any number of other things with it.

Over the course of the past day, we have been using the method explained by Arun Thampi (who discovered Path's privacy violation) to investigate several dozen popular iOS apps. Our findings should bring both comfort and concern to any iPhone user — and to be frank the work of doing a similar investigation on Android and other platforms remains to be done.

Presented below are our findings so far, but we consider this to be an ongoing project. It's nearly impossible to prove a negative, so instead we simply need to test as many apps as possible to determine which apps are uploading your data. Without further ado, here's what we've discovered so far.

Update: Apple has finally made a statement on the matter, promising a future update to iOS that will require explicit user permission to access contact data.