Why not put account that opened for bounties access limit to alternative cryptocurrencies only, because that is what required to earn rewards in most campaign anyway, and use this merit system to control their posting quality there.

Just put button on member profile page asking if the account is for bounty hunting purpose and set their account access accordingly, once this is up we should report any account promoting program out of alternate cryptocurrencies and set their account to bounty hunter.

Account that are not created for bounty or as some of us put it "learning" just go as normal using the old system.