Thread:Sannse/@comment-3416247-20130808014651/@comment-5691231-20130808020228

Users can request CheckUser rights through Special:Contact. But normally Wikia doesn't give those rights unless the wiki has had a long history of extreme vandalism. Generally the requests for CheckUser rights are contradicted.

You could always use Special:Contact though to request a staff member to run the search.

If you're aware of these users being the same person and performing vandalism from wiki to wiki like you stated, you can report it via report:vandalism.