What is stopping someone from creating a bot that will generate bitcoin wallets? Eventually they will find someone's wallet and will be able to steal their coins. There are currently 30m wallets with coins in them, and 10^60 possible wallets. The odds of finding a wallet are tiny, of course, but with several powerful computers running 24/7, they will eventually find some wallets, and generate several future wallets that they can keep in a database. There are probably people that have been doing this ever since bitcoin's inception.