Welcome to the ranks!
A dissident is a person that actively opposes the established order. The term is most often used to refer to political dissidents, usually against oppressive regimes. Political dissidents usually refer to non-violent means, which can range from voicing criticism of the government to attempts to displace or overthrow the established government by achieving popular support and sparking a revolution.
UPDATE: Joi Ito has it right:
People should start investing money in independent record labels who have bands that sing about “sticking it to the man”. The only upside I see is that people get quite creative when they are oppressed. I predict a rise in counter-culture.