And, disable Signature for newbies, don't allow them to join bounties at all before ranking up to Junior members.
This is nothing.
In this way you can create a storm of 100+ accounts every month and join the month after. The only thing is remove also jr members for bounties but you know some managers (or some ICOS) don't cares too much on the quality of the bounty but only on the spam generated from the bounty.
I can say that there are many accounts with a rating higher than jr members who have not received a single Merit since the day of its distribution and they do not differ from spammers.
Yes, I agree that there are many farmer accounts with jr members, but there are also members who did not meet more than 100 accounts in the globe with the Hero member, if I find the time I will make a post about it.
I think spammers are very easy to figure out a bounty manager, but because they say they now get little for the company they just do not want to waste time on it, which is why their reputation suffers.