Because back when the game started, around September-October of last year, they joined with a pair of characters and then created about six aliases and joined with two characters each. And they spammed the holds page with at least thirty holds. All under different aliases. And they spent most of the time that they were in game on hiatus. We did FOAF/mbox checks and there was a total of four different FOAF/mboxes for all of these characters and holds. :\
And after we booted them, they vanished for a couple of months and then joined with two aliases, two characters each. We didn't think to check FOAF/mboxes until after we'd accepted, but it turned out it was them. They didn't make activity (and went on another of their ridiculously long hiatuses), so we swept them.
Last month, they came back. We were actually planning on letting them stay, so long as they didn't create so many characters, you know? But one of their old aliases contacted us and asked us if "they" (meaning that particular alias) could come back with their characters and that threw the red flag up for us. We didn't remove them, but after the conversation with their alias, explaining why we couldn't let them come back, they left with the characters they were currently in-game with.
And no more than a day later, they'd applied with the character they're currently in-game with, and have already begun their holds page spamming.
I hope that made sense. It's hard to explain because it's hard to keep straight in my head sometimes. XD