I think Bob was simply making the point that free speech means you are going to see, hear, read some things you won't like. In most cases, that tells you a lot about the person speaking.

The unfortunate side effect of free speech is all the people who show up to disrupt the site, disrupt the movement, and derail good conversations. But they were identified and removed. Some of them were CIA moles, some basement dwellers, some political operatives, and some liberals who feel it's their job to destroy everything worthwhile. You could sometimes tell if you paid attention to how they interacted and what they said (the little tells). But the funny thing was, as iron sharpens iron, often the people we disagreed with brought out the best in us, and we all learned a lot.