the basic idea is that all media is corporate controlled, and exists to smear these kinds of events. the constitutional basis of allowing media rights is both built on the presumption of, and designed to foster, the expression of a free media as a check on power. when media is owned and operated by the elite as a means of control, the entire basis of that sort of thinking dissolves. free media rights only make sense in the context of the existence of a free media. the activists are no doubt under the absolutely correct assumption that they will gain nothing by talking to the media - all they will get are inaccurate hit pieces, smear campaigns and strawmen arguments in print. absolute non-cooperation with the media, and especially the corporate media, is a rational reaction to the existing state of the media, and their solidarity on the point should actually really be applauded.
but, there's a mob mentality that is taking over here that organizers should have been acting to counteract, rather than encouraging. if the aim here is to draw attention to themselves, jumping needlessly to militant tactics against the media is going to create far worse media than talking to them ever could.
a good example is when the photographer stands on his toes to try and get a shot and one of the protesters pushes him back. that's unacceptable; it's total thug behaviour. and, when somebody gets through, you can't even think about forcibly removing them. it's public property. that's simply assault.
but, you also have to keep in mind what created this. when you raise a generation on the principle that might makes right (in foreign policy, in policing, through reality tv, through fictional media...), don't be surprised when they act that principle out against you.