I don’t think a petition is going to stop these people.
Petitions have a lot of legitimate usefulness for this type of campaign, including embarrassing the oppressors, getting publicity for the good guys, and creating a pool of identifiable supporters for later, more effective initiatives.
Don't let "too little" be an excuse not to sign it. It's the least you could do.
It's better to try to accomplish SOMETHING and fail, than to try to accomplish NOTHING and succeed.