About a week back, I remember running across something (via PSOTD) complaining about the French police picking up bloggers who were publicly calling for people to take to the streets and kill police. This sort of uncritical sympathy for the underdogs (with emphasis on the dogs) is an example of the bone-headed analysis haunting much of liberal politics. There are countless people in the world who are innocent and oppressed--countless people worthy and deserving of our sympathy, yet some people choose to defend someone calling for the murder of the police!
The left, when it chooses to support a cause (and particularly when it elevates such a cause to a cause célèbre) should ensure that the object of its righteous concern is fully worthy of support. We should never make the mistake (which is a hallmark of the right) of thinking that the enemy of our enemy is our friend.