Black Nationalist, "General" Sarasutenseti, predicts a racial "calamity," if Obama loses the election on November 6, 2012. The threat is, vote for Obama, or the cities will burn. Obama's army of stormtrooper-like street thugs are holding America hostage.
Riots are generally spontaneous and not scheduled ahead of time. If election violence occurs, consider it to be a domestic terrorist attack and not just a riot. The more people, who are expecting it, the less likely it is to happen. If everyone is expecting it, many people take steps independently to prevent it, such as citizens being prepared and local police being on alert.
Potential participants are also less likely to get involved, because they know lots of people will be ready for it. So, do what you can to spread the word.