The exchange was hacked in the first week of September following which the perpetrator stole 24000 BTC equaling to a whopping $250,000 at the time. In a blog post, BitFloor founder, Roman Shtylman, called for help and revealed that except for the loss of Bitcoins no other information was lost and he exactly known the amount being held by each account holder.
Shtylman confirmed to ComputerWorld over phone that he had reported the theft to FBI and that he is intending to pay everyone back but, this was going to take time. Shtylman said, "Certainly for me this is a long-term plan, and I’m mostly doing this because I feel it's important to try and be clear of my intention to try and recover the coins."
Bitcoin exchanges have been the primary target of hackers and scores of hacks over the years have resulted into theft of millions of dollars worth of Bitcoin. More information about hacks can be found here.