A video of Olsen being hit, laying on the ground, then police using a flash bang grenade to disperse those attempting to help him, can be seen on Youtube. It's important that this kind of evidence is public, so that people can speak out against this happening, and that's one facet of social media we can be thankful for. This is scary. Western democracies (or 'democracies'?) are behaving as the world's moral compass, yet this kind of unjustifiable violence is happening right in front of our eyes.
Let's hope Scott Olsen gets better, and hope too that this terrible incident causes some police to think again when they use tactics that inflict pain. Already it has prompted an "independent police review", as another Guardian article reports.