OK; I'll tell you from where I come:

COIN is about the suppression of extreme discontent in a country. One of the worst aspects of it is that OUR governments learn how to violently suppress opposition.
Just like OUR governments learn how to do tolerated domestic espionage, domestic surveillance, building databases about citizens and kidnapping/arresting without proper procedure in general in the GWOT.

These two aspects are more dangerous to freedom and prosperity of the West than all those Islamic terrorists combined.

Now I came into contact with someone who had even mentally crossed the Rubicon, thinking of COIN in the domestic context.

120mm, I was extremely moderate in my reply. NOW I'll be honest:
That kind of idea ("domestic policy is COIN" is more dangerous than the worst hate propaganda from whatever crazy Imam you can find.
I am 100% opposed to this.
Nobody must be allowed cross the Rubicon without fierce and overwhelming opposition.