One of the critical measures though is that most activists openly do so. Someone up-thread mentions that MLK was a criminal, and he was. As was Ghandi, and others. But they said here I am, here is what I am doing, and why I am breaking this law. And for civil disobedience to be effective, here's the kicker, they welcomed and expected the punishment.
The idea that we would arrest another human being for sitting at a lunch counter, etc, is designed to provoke outrage at the unjust situation.
The Crito is an excellent place to start in examining I suppose the philosophical roots of civil disobedience: http://en.wikipedia.org/wiki/Crito
Civil disobedience is only one of many forms of activism. The people who ran the underground railroad were in no hurry to make their identities known. Where they any less activists for it?
An arrested hacker activist is a hacker inactivist. Expecting them to allow themselves to become arrested is absurd.
Actually, forcing arrests is a very effective form of civil disobedience. One of the most effective civil disobedience campaigns I have seen was one that aimed to poke holes in wide and loosely defined laws being used by police for openly racist reasons (that is, we don't like your kind here). Some states in Australia have laws that can be used to arrest almost anyone for very little reason. For example, public nuisance, indecent language, resisting arrest (yes, people are often charged with, and only changed with, reacting to police attempt to arrest). Basically the campaign involved indigenous Australians going alone to places they knew would get them arrested, getting arrested, and then refusing bail. When bail is refused you are assigned the first available court session. The plan was a success, after 2 weeks the courts were completely clogged with cases judges would instantly throw out (because the prosecution case was beyond flimsy). Attention granted, laws were slightly changed, and some police officers were charged with contempt of court. Allowing yourself to be arrested is a valid activist tool for change.
Forced arrests only work when the system/population deep down realize how absurd the arrest really is. The courts will happily throw as many "hackers" as there can possibly be into the slammer. Hell, the prison industrial complex has actually made this profitable.
Generally it does seem to be a common attribute. Some activists are also idealists, which is to say they have a view of the world that is idealized based on their principles which is a distortion of reality to a lesser or greater extent.
Living as I do in the San Francisco bay area, I encounter all forms of activists from people living in trees on college campuses (illegally) to folks who provide services to undocumented workers, to folks who expose security flaws on web sites. Of the ones with whom I've been able to talk briefly about their goals, all of them did not grasp that the results of activism are later perceived through the dialog of what the people that 'win' write. (sort of a variation on the winners write the history)
