It is easy to detect the fake entries but the campaign managers are lazy, or they don't want to do it. Because bounty managers are not moderated, only tag from DT members is not enough, so when theymos still doesn't want to control this, it still happens.
Well, cant blame any of the BCT moderator for this. This kind of problem exists in any online forum. A good idea is to have projects registered their bounty with the forum; and pay a small fee. Then give the project a red trust account to tag these scammers when found, so that the BCT forum admins dont have to waste their time chasing scammers.