Any series of behaviors that are technically Against The Rules.1)

This includes the use of alts, as well as the use of exploits and bugs that were not deliberately introduced into the game, in order to get ahead, presumably for ego-boosting purposes.2) Cheating often leads to everyone getting punished by new and buggy modules, much like the teacher keeping the entire class in at their desks because one wanker knocked his over in a tantrum. Said exploiters are unlikely to care and usually begin looking for ways to exploit the new modules.3)4)5)

1)
There are those who will tell you rules don't exist. This is a lie.
2)
Or because it's just plain fnord.
3)
This is called 'rationalization,' when contestants try to invent reasons why their behavior is cool. Humans are particularly good at this, although most of the Island's populations share it to some degree. A few individuals, no longer encumbered by silly limitations like 'ethics' and 'morals', realize that the use of rules and cheating are both being alive in general is apparently just an excuse to be a wanker.
4)
On the failboat, you can teach as many people as you like about the clocked martial arts, despite the advertised day restriction!
5)
Footnote four was made by a wanker. A wanker… FROM THE PAST!