As I passed the lock junction at the top of the ramp something bright and colorful popped up right in front of me and I nearly screamed. It was an ad for a cargo service, created by marker paint on the floor that reacted to movement. It threw a little video into the feed, too, just in case you somehow missed the glowing thing in your face. Usually these markers are only used for emergency procedures because they work even if the power is down. I had never seen them used for ads before. The whole point of markers was that they were the only thing visible in a power outage so it would be easy to see them. It was hard enough trying to get stupid humans to follow the markers to safety without ads popping up obscuring the emergency route—