If the statement issued by the marketís administrators is to be believed, a vendor is behind the theft:
We are sorry to say, but we were robbed on Saturday 11/21/2013 by vendor EBOOK101. This vendor found bug in system and stole 5400 BTC Ė your money, our provisions, all was stolen.
We were trying to resolve this problem, but we were not successful. We are sorry for your problems and inconvenience, all of current BTC will be ditributed to users, who have filled correct BTC emergency adress. I would like to thank to all SheepMarketplace moderators by this, who were helping with this problem. I am very sorry for this situation. Thank you all.
But there are many that donít believe the explanation, and suspect the operators of Sheep Marketplace of having executed a clever scam. In the week leading to the theft, they began blocking users from withdrawing their Bitcoins.
Now that the marketplace is closed down (itís unknown if temporarily or for good), the operators have promised to distribute the remaining Bitcoins to its users, but thatís yet to happen.
Sheep Marketplace has received a big influx of new users following the shut down of Silk Road, and now they will have to move to yet another underground market to do their illegal deals - that is, if they havenít lost their confidence is such sites, and if these online markets will let them in.
Black Market Reloaded, for example, has made it impossible for new users to register.