Michel Foucault, History, Genealogy, Counter-Conduct and Techniques of the Self Excellent points. I wish I was more up to date with current events. Fortunately I am lucky enough to isolate and just do the research. In a way, this is also a technique of the self, having only to engage in struggles within Academia, but I am hoping to take this research and tackle real world problems. Here's one idea I've been messing with in my article
Displacing the Confessional
But I think no less than cultural trappings we should address explicit institutional trappings (perhaps this still falls within your definition of culture), even Foucault said at one point that acquiring a gay identity and being recognized as a group, far from a final goal or a definitive victory, may turn out to be a bit of a quagmire, as it very often happens that it is precisely recognition or the acquisition of rights that places the subject onto a new plane of power-relations. One may also create a continuous and subversive field of alterity, resulting in a gradual takeover rather than a single decisive battle.
In terms of peer pressure or conformity, parresia is not even parresia if one's own status, social, financial or other, is not in danger of being undermined. I think we can distinguish various forms of parresia. We could imagine the parresia of a classical revolutionary who speaks truth to power at a certain point but in a way that brings about radical change, or we could conceive of a receding into the self and taking care of oneself and others through particular forms of self-training and self-discipline. The latter is a form of radical depoliticization of the public sphere.
My point is that "speaking out" or "having an impact" may be a serious political trap unless we qualify these statements. I think the U.S. in particular has an ingenious political field which can create a powerful illusion of change and radical reform, while remaining perfectly within the confines of the status quo. This is another important point for Foucault, the productive element of power.