Isn't the MPEx model just another implementation of the SR model?
MPEx resembles SR on the server side (you don't get to know the IP).
But MPEx management operates more or less openly. MP/PR are easier to find, or at least to identify, than DPR.
It's not as if MP takes great lenghts hiding his name and face:

Though why he would ride a horse instead of a camel in Egypt is a great mystery.

A better question would be why he's wearing an ill-fitting 3 piece suit in the freaking desert. Photoshop?