if your funds were stolen from multibit it has nothing to do with multibit.
It means your computer is compromised. Using qt OR blockchain.info
on the same computer will make you lose more money.
But my computer was not even on.
What if the hacker had access to the wallet backup and the password? It wouldn't need my computer that way, right?
Not he wouldn't, just to add I use armory for any large amount of coin. Electrum offline storage also works well.