Hackers in the game exist for a multitude of reasons, but there are many types of hackers that exist as well. What Hacker is which is listed on this page here, but remember, no Metagaming! If a Hacker isn't revealed, and you instantly know, it's Meta.
These sly hackers implant viruses via their own internet connection, these viruses can do many things, from taking control of other players, to altering an area's or NPC's code. The most skilled of Virus Creators can even alter their own data.
Script Coders are hackers that have made their own trainers in order to grant them items that would otherwise be unavailable to get, this includes locked weapons, unreleased costumes, as well as having infinite ammo for all weapons that aren't from the Launch release, it can even include having God Mode (to a degree) as well as infinite SP, and no spread. Script Coders however, are often stopped a moment, or a few moments after they're spotted in a game, and the connection is often closed by a GM, thus resetting the Script Coder's process.
DDoS attackers, simply put. These Hackers simply just want to ruin everyone's fun by overloading the servers, though it's often risky to pull such an attack off, especially should the server be equipped with DDoS protection.
- Kazuma Ochitsuki (Not revealed, Virus Creator)