Has there been another as-yet-undisclosed breach at Yahoo?
With the recent release of iOS6, we have noticed a marked increase in support calls due to meetings having the owner of the meeting changed (sometimes called “meeting hijacking”).
Among Microsoft's recommended work arounds;
Block iOS 6 devices — Exchange server comes with the Allow/Block/Quarantine functionality that enables admins to block any device or user.
Tell users not to upgrade to iOS 6 or to downgrade their devices – This solution may work as a temporary fix until Apple provides a fix but many users may have already made the decision to update.
The Metropolitan Police Department (MPD) recognizes that members of the general public have a First Amendment right to video record, photograph, and/or audio record MPD members while MPD members are conducting official business or while acting in an official capacity in any public space, unless such recordings interfere with police activity.
There's no future in time travel.