One of the blogs I read is Schneier on Security, a blog about the security mindset, and security issues in and out of aviation. Bruce Schneier is a security consultant who has decided to bash his head against the wall in a public forum. The blog gets a little repetitive, because it's mainly driven by news stories, which themselves are repetitive because people don't learn from previous mistakes.
Comments on a recent discussion of the indiscretions of US sky marshals included the not-new suggestion that the cockpit be completely separated from the cabin, with separate food, water and washroom facilities for the pilots.
Meanwhile someone else raised the also not-new suggestion that "Then the only possible target for the pilot to shoot will be the co-pilot. Which, if you arm them all and wait long enough, is sure to happen."
I stopped reading and got the best laugh at a follow up comment, "If you were to survey current pilots, you'll find that there are several pieces of equipment more likely to be shot before the co-pilot."