They are using some kind of vanity URL software and just making many permutations of URLs so they can't get blocked.
Kind of like the spammers constantly calling my cellphone...all kinds of weird phone numbers show in my call list, but when I called back once, it said the number was disconnected or no longer in use. I long for the good old days when only family members, friends or the school would call my cell number...technology these days is being used to really pester us!!
Rumo ~ rescue shepherd/husky mix