Interesting read - This is actually how a ton of game trainers/bots are made (especially ones used by Chinese gold farms in MMORPGs), along with private servers (except the other way around, where you send packets to the client). For some games, the bots are advanced enough where they can interact with all of the game's network protocol and behave similarly to a human, all while just being a 'terminal' for the game that sends custom packets. Hacking games via packet manipulation is nothing new either - I remember one of the big MMOs ~10 years ago having an exploit which would allow anyone to delete anyone else's in-game guild, and similarly, log into any user's account under some specific conditions.