I remember/know of one case so far where a group wanting to move from Yahoo couldn't use the old group name. A 'competitor' used it as an alias here just so the group moving couldn't. There are liable to be more of these as GIO grows, so I hope Mark has something in place to handle it. Allowing aliases isn't something I'd do at all because of the ensuing headaches, but a low limit should help.
This group alias issue is one of those bits that can get somewhat complicated.
If the aim of the no-more or limited aliases is to disable or discourage/curb squatting (malevolent or not for that matter), that can easily be defeated and the same net effect achieved by smartly creating & configuring groups, it would just be a bit more work; you can't (easily) stop/discourage someone knowledgeable from malevolently doing what that owner did, neither here nor on the net.
You can however monitor them for recurring/suspect behavior.
I don't want to start a philosophical discussion on the ethics of group name (or domain) parking, there are valid points from both sides of the debate. Plus after all, Mark implemented it here (and it has remained, so far), apparently it must have some type of value to him. I don't know the origins, maybe it was just a convenience gifted to the paid groups due to an Enterprise request, I don't know; only Mark knows about the value of this feature to him and whether taking it away could present the potential impact of removing a convenience feature for prospective clients. And if applied retroactively it could cause complications to existing Enterprise groups using it, so if that was to be avoided it may be yet another grandfathered thing now that needs tracking.
PS: One of my other selves, the green-eyed one, whispered to my ear "paid optional feature", but he's known to be a troublemaker, I don't know, maybe I should throw him out of the room.