Has this ever happened before?
Private Key Hacked by brute force
We are working on this now. We are devising an algorithm that exploits certain weaknesses to get to address keys. More on this later.
The scientific answer to your question is 'Yes'. But it is challenging.
The Master troll at work again, so just ignore him. The next thing he will do is to direct you to his master list of hacked private keys. ^fake^ Just test him and create 100 or 1000 bitcoin addresses and send it to him, so that they can prove that they found 1 single private key out of the lot. You will wait forever, because it cannot be done.
The logical answer to your question is `No` because it is basically impossible.
The day when they break ECDSA or SHA256 or RIPEMD160 algorithms, the whole financial system will collapse, because most of their systems are based on it too. ^smile^