Basically, it depends on the bounty manager. As far as I know, there is no specific explanation regarding "one person joining the signature campaign with more than 1 account on different forums". On the rules, BM only said "cheating are prohibited". Not sure if using some accounts from different forums is categorized as cheating. In my understanding, only the Bounty Manager or the team member of Bitgame who can decide whether it is cheating or not.