They are paying for it now. Virtually every ISP out there caches content and you are looking at somebodies last viewed page. I remember when Cablevision came to our radio club as they were getting to roll out their internet service one of their points about it's speed was they would cache the entire internet in their office so that when you wanted a page it wouldn't ever leave their system (they immediatly corrected it saying they would cache only the pages other people requested when we asked them how they would cache the entire internet). It's proably not hours old, and I doubt they would not refresh these pages during the flight, but many people, without having a clue it's happening, are getting cached pages thinking that it's live.