It won't happen, but let's pretend you gained access to an address of some one that has 10BTC in it, what will you then do? Steal the coins?
Probably 10 BTC I wouldn't transfer, too low for the risk.
But imagine you get any address with thousands of them? Would you judge anyone who dares to transfer them?
As satoshi said, the ownership of bitcoin belongs to the one who has the private key, not to who thinks it "holds" them.
Nobody owns bitcoins, the only thing you own is a private key.
Well, I'm not going to judge someone for transferring large amounts of Bitcoin from an address they found, but they better be prepared for the consequences if it turns out to be stolen or the rightful owner comes knocking. As Satoshi said, it's all about the private key, so whoever owns it wields the power.