I agree-----a very slippery slope.
Most of the Muslim problem could be solved by better intelligence and protection of our borders.
Of course, it all depends on how you define a "civil liberty".
This article defines "infiltrating a Muslim group" as a violation of a civil liberty.
Thus, you have a situation where the methods used to obtain "better intelligence" is defined as "you are violating Muslim civil rights".
I have no problem whatsoever with the FBI "infiltrating" any group I or any of my family belong to as long as the FBI agents pay their membership dues on time. We have nothing to hide and anyone is welcome to During the early 1960's, the joke was that half of the membership of the KKK consisted of Government agents.
Why should it be that infiltrating white supremacist hate groups such as the KKK is considered enforcing civil rights while infiltrating Muslim hate groups is considered a violation of civil rights?