I hate to be that guy, but non-lethal force doesn't mean anything... Here is what happened in Germany not so long ago:


Just a "harmless" water gun. Non lethal force used against peaceful protesters... Anyways, that guy lost his eyesight. And I can't imagine rubber bullets being much better.
Not saying that it is as bad as lethal force, but yeah, if shit goes down, I think it's safe to say to watch out for yourself.