[6yyyyyy]

Oh yes, absolutely. There are a number of "alt shops" selling Minecraft accounts accounts for a few cents each.

Most of these accounts have security questions set, so you can't change the email and truly "take ownership" of the account, but it's good enough for cheating on servers.

Some shops even have an API for generating accounts or tokens, so your hack client can have a feature where you get a new account right from your game. Get banned, reconnect in a few seconds.

[vintermann]

The last point sounds like a security vulnerability of some sort? It shouldn't be hard for Mojang to issue unforgeable tokens.