Both the Times and the Guardian describe this as a “data breach”, but I don’t think that’s entirely descriptive of what went on here. When I hear “data breach”, I think that a password got stolen or a system was hacked into. But Facebook VP Andrew Bosworth tweeted that there was nothing that was stolen — users willingly gave their information to an app, which went behind their backs to use the information in a somewhat sketchy way that users did not expect.