Conceptually, the filtering is little different. This policy, however, is very different in the severity of consequence. The superficial story is that the filters have been implemented. No different than Wikileaks, really. The memo and basis for the filters is a very different story.
The memorandum distributed to address the policy mentions sanctions for soldiers found proliferating the Guardian material. Most concerning is that the filters are described as preexisting filters that prevent the mixing of classified information and unclassified systems. In other words, the Army is classifying Guardian articles as TS level content. This is unauthorized for unclassified systems and to be read by soldiers who lack the appropriate clearance. By unauthorized it is meant to mean punishable under UCMJ as a security violation; it's a criminal offense.
The memo also charges leadership with accountability for establishing a vigilant command climate to underscore the secure handling of classified information. Very likely, this means leaders are empowered to implement local measures to ensure unclassified systems operated by soldiers do not house classified information. This is essentially treating a soldier found with an article from Greenwald the same as a soldier who transferred data from a classified system.
The criminal conduct aspect here is, to me, very different from restrictive corporate firewalls.
That policy was never rooted in sound logic, in my opinion, but it is still active. Outright blocking of the Guardian newspaper was probably not necessary - in our case, fear of persecution was enough to keep us from visiting Wikileaks, at least at work - but it is consistent with their policy and motives.
To stick their heads under the sand like this is shameful.