I didn't install any "calculators"
I don't do skype
I haven't downloaded anything for Diablo 3.
I don't even have "screen shot"/Video making software to record my battles. (fyi - this should be built in.)
I own a Logitech but I've never installed they're "macro" software.
I play this game legit.
Yet, I got an in game purple whisper message:
[blizzard01] whispers: [Blizzard Game Masters] Hello dear players the system checked out that you're using an unapproved 3rd party software. Please visit http://GM-BATTLE.NET and verify your account information.
Otherwise, we will suspend your account.