Likewise to the above on Siren; Offensive individual enters the Novice Network, Dumps a block of All-caps text (likely done with the in-game macro system) and jumps world before a kick can be issued. The only GM contact I've received directed me to submit feedback to the Website/Companion Feedback Forum. Post here.
In Short Mentors and Moderators need stronger tools to combat this. Offworld Kicks to kick a user that has jumped world trying to evade a kick, Cumulative kick duration for sprouts, Kick reservation to Kick an offending user when they return to the world that issued the kick, and Inviting Mentor lookup. Maybe these trolls beg for invites in the major cities, maybe it's one disgruntled mentor on another device invite free-trial throwaway accounts.
Regardless; These individuals have found a way to disrupt and offend with no repercussions and Square Enix seems content to allow this to continue unabated.