Formula One racing has reportedly agreed to permit Bahrain to host a race later this year. The event was to be in February, but was rescheduled due to the protests. Some racing teams apparently will boycott the event.
I think that many online petitions are a waste of time, but this is one instance in which a large number of "signers" might deter both racers and advertizers from participating in the Bahrain event. The petition is directed toward Red Bull, which sponsors an F1 team. [Added: Red Bull is also sponsoring a drift competition in Bahrain in June.]