http://www.nydailynews.com/news/crime/new-york-suv-biker-beatdown-biker-charged-article-1.1490406 So the undercover was some guy who "infiltrated the Occupy Wall Street movement?
What wouldn't give them the rights? As long as what they're doing is not against the law, I don't see why they couldn't.
and if said political movement involved activity that was against the law, I see no reason why they shouldn't be infiltrated , either. goes for Occupy and biker gangs.
The FBI has opened a gang investigation file on the Juggalos, even though most of them are just redneck music fans, a few of them might engage in illegal activities like drug dealing that's not linked to the group at large.