Of all crimes, sedition should include exclusion from society. One can hardly declare them outlaw*, there being no uncharted country whither the criminals might flee. So, prison is the only option.

*Outlaw in Germanic common law meaning: An outlaws property and self could be taken by anyone without recourse.

How eager they are to be slaves - Tiberius Caesar

Coulda tripped out easy, but I've changed my ways - Donovan