[Buge]

That's essentially what brainwallet did. Your bitcoin private key was deterministicly generated by your password. So using a list of common passwords, private keys could be pregenerated by attackers. So anyone who "created" a brainwallet with a weak password would get their money stolen the second they deposited it. Brainwallet got so much hate from people that used weak passwords and got their money stolen that it was shut down.