Now the UM website is back online with a statement they've shutdown. Link to the legal disclaimer with all the statements referring to their right to shut down at any time with no notice, no refunds, and no obligation of any kind to return funds are all highlighted.
Here you have it, the scam is official now.
(Note for those scamming bastards: Putting such a disclaimer will not help you, if Bitcoin succeeds the bounty on your head will be enormous. Hope you are ready to pack your stuff and hide in a cave)