The Golden Gate Bridge has surprisingly strict guidelines about how groups can conduct a protest along its walkways. According to the Chronicle, as it stands small groups of less than 50 must apply for a permit to hold a protest march across the bridge and the usual tools of the trade: signs on sticks, megaphones, etc are banned from the walkway altogether for fear they may ruin drivers' concentration. You can't even protest after 2 p.m. on a weekend afternoon - do you have any idea how hard it is to get 49 supporters of Code Pink to come out on a Saturday morning?
Those regulations, originally intended to prevent spontaneous acts of civil disobedience from distracting bridge commuters and have been in place since the pre- driving-while-texting days of the mid-90s, were recently ruled to be in violation of protesters' rights to free speech by a Federal U.S. District Judge. One of the plaintiffs even found this out the hard way when he headed to the bridge prepared with a sign to protest China's policy in Darfur during the Olympic torch run in 2008, but his lack of proper permitting meant he was "grabbed" by CHP cops who confiscated his undoubtedly well-crafted sign.