never heard of this website, but it's proof of exactly what i said which is they found 19321 private keys in 50771 Bitcoin addresses with transactions. just for bitcoin addresses so to people who say it's not possible here is a good proof that it is possible and can be done with a large enough of group with good machines with some luck
It's proof that brainwallet and private key chosen by human/generated with weak RNG are vulnerable towards brute-force attack and few other attack (such as dictionary attack for brainwallet).
Precisely this. OP may find
interesting if he wishes to see just how bad humans are at entropy.