I think it's usually an accident. I mean, who anticipates rioters blocking streets, and how do you ever know which streets they're gonna be blocking?

Since this is becoming a common theme, maybe someone should write an app for that. They could incorporate it in to the traffic app on your phone.

"Protest. two. blocks. ahead. Take. alternative. route."

Of course, such an app is probably racist. Who are you to avoid having your family accosted by anarcho-communists and race rioters? Those streets are, after all, their streets, as they can't seem to stop reminding us.