We have all read stories of coins being sent to wrong addresses (typos or badly copy and pastes)
What would you do if 100 Btc landed into your account? (unfortunately this has not happened to me yet)
If that will happen I think I will be surprised and so happy at first since that is the first time I've seen a huge amount of bitcoin in my bitcoin wallet, I'll never think that it is a wrong sent bitcoin since it is not possible to mess the address up with that number of bitcoins. If the owner contacted me, yeah, I will be taking it back, but if not, I guess it is mine now.