Re: Even the Merit Point are motivating to hack BTT accounts! Dumbest case.
Unfortunately, there is no way to prove to us it wasn't you that did that. 
Maybe someone offered you coin to leave those merit? (Not accusing, just giving an example)
If he sent all sMerits himself, I don't think that he would make this thread to get attention.Maybe someone offered you coin to leave those merit? (Not accusing, just giving an example)
I see some Spanish posts and any Russian posts in your post history, so it's not likely that you awarded your alts with all your sMerits. But theorically, it's possible that you sold your sMerits as Vod says
Anyway, you should enjoy that you still have access to your Bitcointalk account after that. It's a good lesson that you and other users need to set more difficult passwords than you had.