One question that you are not asking is whether this decision was affected in any way by the Megaupload case. If I were Dropbox, I would see arbitrary action b

One question that you are not asking is whether this decision was affected in any way by the Megaupload case. If I were Dropbox, I would see arbitrary action by the US authorities as one of my greatest risks, and would do whatever it takes to stay in the good graces of the MPAA, given the apparent influence that they have over US law enforcement.