The idiom "try to get your goat" describes the intentional act of one person attempting to upset one or more other persons. Goatstolen is disposition of a vicitm of this intentional upset.
The word describes someone who is or is acting upset.
Did you hear Bob get worked up when that guy was camping him in the online game, Bob sure was goatstolen.
I just kept poking holes in his logic until he was totally goatstolen.