There is a long history of violations of constitutionally protected activities and rights in the US.  One that's grieviously under-reported and unrecognized is the Freedom of Association (this would include such rights as not having to associate with gov't spies, provocateurs, moles, professional disruptors, etc...  in your contitutionally protected association).

The book "The War at Home" describes how COINTELPRO (an FBI operation) was used to "misdirect, discredit and disrupt" any organization/individual not to its liking.  (Generally anyone with an activist agenda perceived as threatening by large corporations.) It makes for chilling reading, but it will give even the most polite Boat-Rockers new eyes with to perceive their activist experiences.

We only know of COINTELPRO because some brave citizens actually burglarized an FBI office, found the incriminating documents, and published them!  At that point, congress was compelled under public pressure (this was the 70's after all) to order them to shut the operation down, which they nominally did.

One doesn't need to be a cynic to assume they just decentralized and renamed the operation.  I've known many activists working on some incredibly benign campaigns tell stories of organizations and work destroyed by events that look like they were scripted out of "The War at Home".

If you can't recognize it, you can't see it.

I wrote an editorial in my newspaper last month advocating against a local school bond, mentioning the housing slowdown allowing a little breathing room.

Got flamed.