And it's a freakin brilliant move by the spies owner. He controls Hawaii with zero cost and zero risk.
He's the only person in the whole world that can control if and when Hawaii becomes available. (unless someone else puts a spy there too

) and when the player is ready Hawaii will become vacant for him.
However as I mentioned before if someone else puts a spy there... It becomes a waiting game. And one based on luck. As the first one to move loses control of the islands opening time. However the 2nd and winning and controling player can only realize he's the 2nd player... By moving. lol.
And what if there's a third or fourth or fifth? I'd just give up on it, and take hawaii when he finally builds on it. If he does. If he doesn't then he never would have anyway and you would've wasted a lot of time.
The only other option would be to bombard and attack him relentlessly with msgs telling him to move his spy or die.... but then I guess you'd have to know for sure who it was.

and again you'd be banking on the fact that he's the only one.
Just let it go. Hawaii's not that freakin great anyway. You're not only isolated from your enemies but allies as well. I'd rather be on a big landmass surrounded by friends and ppl I trust.