Wouldn't it be better to use stealth and lead an unseen attack on the protestors? Like, have a team of gunman with tranquilisers a hundred or so meters away hidden in windows, then simultaneously tranquilise the entire Phelps protest? Admittedly it would be funny, but seeing as the Guard people at the funeral were blocking view of the protest, it isn't like it would cause too much of a commotion. Also, if the assaults were repeated a few times at various protest locations the WBC might start getting a bit scared.