Microsoft's motivation for helping Tunisia regime likely profit
In previous entry I detailed Microsoft giving SSL root certificate to Tunisian regime of dictator Ben Ali: http://news.ycombinator.com/item?id=2138565
The motivation for such an action is simply profit. All Tunisian government web site use certificates issued using the root certificate and because root certificate only presnet in Internet Explorer Tunisian people are forced to use Windows/Internet Explorer for secure access.
So Microsoft profits from this arrangement and allows the regime to use a certificate that can be used for man in the middle attacks.
A win win situation.