I almost closed my allcoin account numerous times in the past 12 months. My account kept getting frozen and the penultimate time was a few months ago when it took a couple of weeks for Mark? to unfreeze my account. It was pretty obvious it was a one man operation. I also didn't think he was making that much money. The volume of all the alt coins on this exchange has always been very small (going by http://coinmarketcap.com/exchanges/allcoin/ - this doesn't show historic volumes). And if he was only making 0.5% of that, well I did wonder how long he would be motivated.

So I reduced my holdings there from 4 to 3 btc. I couldn't bring myself to close out because I had made over 3 btc in the previous month. I reasoned that as it was "profit" it was worth the risk. Greed over sense. I've been taught that old lesson again.

Still I would like to believe in Mark's integrity, he didn't strike me as a fraud. I therefore would give him the benefit of the doubt and say the closure might be from sudden illness, or 3rd party theft of coins scenarios.