This alone would be HUGE. All Proof of Work currencies are plagued by the threat of a bad actor (or several in collusion) wrecking the network by double-spending or other malicious behavior which is made possible when they control 51%+ of the network's hashrate. Our very own currency is no exception: coinmine.pl has had over 50% of the hashrate for many weeks now, with no signs of that changing anytime soon.
I agree on that. There has to be a way to prevent such things from happening. From what I know two major actors are mining on coinmine and together they have between 30 and 50 GH/s.
Any respectable pool operator should at least try to take measures to prevent his pool to become that large and endanger the network. I understand greed but that same greed can put what earns you money in jeopardy.