If you have the "rollback" user right, you get a "rollback" link in various parts of the user interface. This is currently a confirmation-less link that will revert all of the edits a user has made to an article (cf. [[WP:ROLLBACK]]).
It's _really easy_ to accidentally click this link. It happens fairly frequently, particularly for users on touchscreen devices (an iPad, for example).
I couldn't find a bug already tracking this issue, so I'm filing this one.
It may make sense to require two clicks for rollback links (this was similarly proposed at bug 47658). The current assumption that power-users (i.e., users with the "rollback" user right) aren't clumsy and won't accidentally click this link is clearly faulty. :-)