The Darfur conflict, as far as mass death of people get, gets very little attention in the world media. I've always wondered about this hypocrisy. One of Google Answers clients, apparently not a fan of the Sudanese government and its atrocious policies, has asked:
"Does a US citizen currently violate any US law or risk any possibility of arrest in the United States by actively participating in the violent overthrow of the government of the Republic of the Sudan, a country with no extradition treaty in place with the US?"Pafalafa-ga answered this question, titled "Legality of a Coup Plot". Basically, the answer is that if you're not active in the United States itself, there are no laws that address it. If you are, though working in the US, there might be a problem.
But then again, you can alwasy be active in non-violent organisations, such as Amnesty International.