I have installed it on both of the computers in the bedroom -- the one that is theoretically Gretchen's and the one that theoretically belongs to the girls. This did not prevent fighting and sobbing tonight when Julie accused Katie of taking the computer that she had set up. Then I was told that Minecraft wouldn't start on the other computer.
Which is true, I suppose, if you don't press the "Play" button.
I threatened to impose severe Minecraft restrictions which provoked more tears and hysteria.
Well, we'll deal with it...