I didn't read Solrize's comment as saying "There shouldn't be paywalls," just asking the very legitimate question as to how they will interact with federation.
Interestingly, 404 just solved something kinda related: they developed a way for subscribers to get a custom RSS feed address, so they can access paywalled articles directly in their RSS reader. TMK, they are the first publication to do this. I imagine they would do something similar for federation. (I believe that if any of the custom RSS feeds show huge traffic numbers, 404 shuts it down, but I'm not sure)
The Shoe Bomber was caught because he was trying to light a fuse with a lighter. You cannot light a bomb with a pocket knife. If you want to ban something from planes, ban lighters