Loophole Abuse/Fan Works

Examples of Loophole Abuse in Fan Works include:

Fanfiction.net explicitly forbids Real Person Fics due to defamation concerns from the persons portrayed and/or their relatives/estates. Not that it kept people from writing one anyway, especially if the persons in question are either Historical Domain Characters or if they were portrayed in a work of fiction (examples of which include Niki Lauda and James Hunt in the 2013 sports drama Rush and the officers of the 1997 epic Titanic).
This is the specialty of Hermione Granger in the Harry Potter fic The Parselmouth of Gryffindor, to the point that at age 13 she is already in the process of engineering an unexpected resolution to the Prophecy concerning Harry and Voldemort by exploiting its Exact Words.
In the How to Train Your Dragon fic A Thing of Vikings, Snotlout is forced to make an oath that he will never lead dragon riders on raids after he assembles an unauthorized attack on a nearby settlement. Not long afterward he departs for Constantinople to join the Varangian Guard -- where (not entirely of his own free will) he is put in charge of training and leading dragon riders for the Byzantine Empire. He justifies it to himself (and later Hiccup) by pointing out that the Exact Words of his oath didn't prevent him from capturing and training dragons and their riders, nor was any of the military actions he led a "raid" in the Viking style. Hiccup doesn't buy his justifications and exiles him from Berk.