Bitcoin is a virtual cryptocurrency present in the game. Bitcoins can be traded for in-game money (or vice-versa).
Bitcoin has unique anonymous features.
The only way to login on someone's else wallet is by sighting it's key on the victim's log. This happens when:
A wallet is the equivalent of a bank account. The wallet is stored on your software page, and publicly lists how much BTC you have on it.
In order to collect bitcoins you need to install the miner virus. You will also need a virus collector.
The value of 1 BTC is the same of real life's bitcoin buy price. (It might be rounded).