How would that be suicide? I'm not thinking of just getting a few hundred people and telling them to go to some Oz-like prison. And I'm not talking about some organized movement like OWS where people protested over issues related to actions perpetrated by other people.
I'm thinking of a situation where a large number of people would be cooperatively going to submit themselves to the penal system related to things they did and believe that is not right to be punished for. Most likely, they would get results even before the actual collective "turning in". Can you imagine what would happen in the US if the good majority of the 7 million undocumented immigrants [1] organized a movement that announced they would turn themselves in?
Additionally, why incur the personal risk from confession when there are plenty of cases to be had that are already charged? OWS comes to mind.