Do you think that it is the job of the moderators to fish out cheaters with multiple accounts in campaigns? It will be fine you are informed that campaigns are not the project's of the forum, so the moderators or admins care less about it.
If you find cheating accounts, tag them and create a post in the reputation board and many people will be willing to investigate the matter.

I'm not really sure what's your problem. Did you just made account here to complain that someone participate in bounty campaign with multiple accounts?  If yes, then you're asking in wrong place. Moderators isn't responsible for bounty campaigns. If someone is abusing bountry, it's manager job to find cheaters and kick out them from campaign.