Haha, very funny. I already considered all the likely responses, including that one. I'm not certain that this is the one they'd give, but there's some chance I'll be around them again with a little more time and I could test it out. Sound good?
In the meantime, let's see if you've done any material analysis or critically thought about this! When they said that, what possible replies would I have? You can assume that they have the usual set of other signs that protestors tend to have. (I spotted most of the usual ones there.)
I mapped out a bunch of conversation trees in my head while I was walking past. I couldn't find any branches where the protestors hadn't either missed something really important, or were endorsing two goals which were entirely opposite from each other.
But, anyway, yes, I anticipated that response. What do you think my responses were going to be? (I considered three; if you pick one reasonable one that's enough.)