We had measures beyond IP checking that we use but won't go into for obvious reasons, but we're not going to get into the business of banning new members just because they seem similar to old ones. I find it ridiculous, frankly, that people would call for the banning of a member without any sort of hard evidence of any kind. That Blaze_18 and Avada Kadavra were the same person clearly shows that our common villain is quite capable of posting in many different styles, so banning on suspicion would basically see me turf every new Indian-supporting member.
If you want these members gone, I think you should tackle it from a different angle than "we think they are multis" because it'll get you nowhere without evidence. I wouldn't necessarily disagree, FWIW, that the place could deal with some more common sense regarding the quality of posting from new members, but that would require us to be openly subjective and almost unfair in the interests of overall forum quality, which is something we'd have to have to utmost trust in the community to do. I'm sure we'd get accused of all sorts of biases if we just started banning members for posting what we believed to be provocative trash but short of trolling, as we already get accused of being pro-subcontinent AND anti-subcontinent on a daily basis.
The hardest thing about this place is finding a balance between keeping the quality of the discussion high and giving everyone a completely fair medium to have their say. We don't want to be the opinion police, but I've seen a growing trend of the infractions we've given out following a standard pattern of someone posting a biased or arguably ludicrous opinion (that's genuine, and not trolling) in a patronising way and then someone replying by insulting that poster (rather than the post itself). It frustrates me that some of our (IMO) better members either can't help themselves or don't quite know where to draw the line between attacking an opinion on a specific issue and attacking a member as a whole, particularly as our err less high-quality members seem to get it spot on. I just don't think I'll ever understand why people seem to get so much more satisfaction out of telling someone they're a **** member than saying a specific post they're replying to is ludicrous, remembering of course that one will get you banned and one won't.