That's not a biased list of options at all fossil!
If I saw somebody doing something like that I would (depending on the circumstances) go with option 3 cos somebody probably would start beating the snot out of them!
Practically, you cannot reason with somebody who is worked up enough to do that, so while I would be saddened and disappointed, because it is not illegal to do that here I would not intervene and would probably pull out my camera and try and get some pics to sell to the paper (close enough to option 7).
If I met them at the pub later though I would ask them why they felt that way about my country and then either:
- agree with their issues, but not their method of protest, and get them thinking about how we can change things as well as the good things here too as we had a drink together,
- disagree with their point of view, as well as their method of protest, and put across my point of view as we had a drink together.
If they were still being unreasonable I'd probably go with option 12, then option 6.