There's another way of reading that FINCEN stuff which is essentially "if you own the machine and mine from it for yourself, you don't need to register". So it doesn't matter if it is co-located in a hosting farm or in your home, it's your miner with the income going to you. Mining contracts are a distribution from the company that owns the miner (i.e. not you) to a customer who has paid to receive a share of the earnings over a period of time. In that case you don't own the miner so the bitcoins are being transmitted to you. KnC always went to lengths to say that if hosted it was your specific miner and would be shipped to you at the end of the contract, so I don't see how they would be caught by FINCEN as well as the fact that they're outside US jurisdiction.
This makes sense to me. If my miner is in a hosting facility and I am paying for power and network for the hardware. It is still my hardware and if I am dictating where the BTC go then I am mining for myself.
US out of my BTC!