Apple's annual developer conference in San Francisco.
Widespread iTunes and App Store Terms and Conditions Bug Preventing New Purchases and Downloads [Update: Resolved]
When they accept, they are then asked to agree to them again and again. As a result, new purchases and downloads from iTunes in the Cloud cannot be made. The issue appears to be affecting all purchases from the App Store and iTunes store on both iOS and the Mac, as well as the Mac App Store and iTunes Match. It's also affecting the viewing of purchased items on the Apple TV.
We've reached out to Apple for comment, but until the issue is resolved many iOS users will be unable to purchase apps or media content.
Update: Commenters are reporting that the issue is not affecting international accounts. Users have successfully downloaded apps with Singapore, Hong Kong and New Zealand-based accounts.
Update: The issue appears to be fixed.