I'm at the point where every time someone yells at me for protesting and tells me how useless it is, I chalk that up as a little sign of success, however small. If this guy is taking time out of his day to rant at me at length about what I'm doing, that means others are likely taking notice too.
Do I think protesting is going to magically solve the issue? Of course not. But it's something I can do to bring attention to the issue, spread awareness, and encourage others who feel the same way but might feel alone or unsupported about it. I'm always happy to hear about what else I can do to better effect, but somehow that never seems to be something the naysayers are willing to provide. It's always just tearing down, no advice or building up.
Eyes up here, Jon