I logged in this morning and only my main character (the one I was playing last night) lost all their gear + all gold.
All my other characters are fine and my stash is intact.
This leads me to believe that this could only be a failure on Blizzard, a database issue. I've submitted a trouble ticket.
Again, what's more likely?
A) A "database issue" that only affects one character on one account out of hundreds of thousands of players.
B) You got hacked.