I'm sure the topic has been covered well enough in the media but there's one image specifically that grabbed my attention. It's one for all the firearms aficionados - remember that this was taken now (as in, November 2010).
And I've just found a video of it in action. A police officer can be seen using the MG in question at about 1:18 on the vid.
http://www.metacafe.com/watch/428337...aniero_brazil/