I would say that the most promising way to prevent politicians and criminals from trying to censor through killing journalists is to retaliate the killings by killing them back. It is not something that I necessarily support but I do not believe that you will get anywhere by trying to go through the lawful route. At best it will be ignored (see the wikileaks revelations, did you have many people go to jail?). At worst you might end up getting killed, just like the previous journalists that they murdered.
Requisite mention: Jim Bell's Assassination Politics.
I doubt that it'd ever work. Too few of the oppressed masses would ever be motivated enough to participate, or would risk it, even if they were. And so it'd mostly get more journalists etc assassinated.
But still, it was a cool statement, back in the day.
