Then (and sorry, I know it's a tired thing to say) I had a kid.
And my god, the people who will go FAR over the limit right down your street where people are pushing prams, kids are walking along, etc. is astounding. It's enough to make you hate all drivers, though a moment of reflection reveals that even if 1 out of 100 drives dangerously, you'll remember that 1.
We need car control every bit as much as gun control, and speed cameras are a big part of that. People die when drivers are left unchecked. Disproportionately, it's people not inside cars.
Of course, people also die from the emissions coming out of the tailpipe, which is what these protesters seem to want to do freely. "Oh, your grandma has emphysema and lives near the road? Tough shit, I want my cheap diesel."