Isn't paranoia a wonderful thing! This isn't just confined to the US, C-47/Dakota's are now banned from flying passengers in the UK because the cockpit doors are not secure enough to meet the new EU security legislation. The cost of upgrading the aircraft is prohibitive, therefore in 2008 it finished
B-17G Sally B was grounded for a year, again because EU regulations placed her in the same insurance category as a 737. Unlike the US most UK warbirds are flown on the Civil Aviation Authority (CAA) "Permit to Fly" basis and therefore are not certified to fly paying passengers, Sally B is no different and cannot re-coup some of the money using the very expensive CAA Hire & Reward category.
As for the PC brigade trying to ban the word Warbird, they can go Foxtrot Oscar!!!!