Those people are security selected from China and their task is only to escort the torch.
They have no executive powers and have to obey US law.
I don't see any other immediate action avaliable other than simply shoving the protestors out of the way while letting the local police arrest them . Are you suggesting that they should sit the protestors down in the middle of the relay and politely request each and every one of them to kindly take 10 steps away from the torch bearers?
There are even security guards present at a pop concert or any public event in the US, so why aren't the Chinese guys allowed to be there?
I think those people describing them as "thugs" are very ignorant and doesn't know the purpose of security!