Yeah, the whole "You can check the IP addresses!" argument is a non-starter, since none of us can do that.  And as I wrote in my previous post, it's possible that this is some kind of family bounty farm (though the thought of that chills me to the bone) but the more likely explanation is that these accounts are controlled by a single person.

Unfortunately, there's no way to tell for sure--and that's why I stopped tagging suspected merit abusers a long time ago, in addition to the fact that Theymos doesn't really want them tagged unless the abuse is blatant and extensive.  The argument could be made that there's some bounty cheating going on here, but that's up to individual members to decide as to whether to tag these accounts or not.