Last year I missed a flight at EWR because the security machines went down / lost power (something that has happened multiple times to me now at EWR, but never anywhere else), so I had to be rebooked. Actually I missed it by just a couple of minutes; with my luck the flight's gate was quite a hike/run from the C checkpoint. The GA (of course) refused to assist with rebooking which forced me to go to the customer service desk, which (of course) was in another C pier, so I had to again walk the length of almost 2 of the piers to get there.

All the flights to my destination were Y0 for the rest of the day, but the agent at the CS desk made a call to get 1 Y seat released to rebook me on the next flight. I was just a UA gold. So that was nice.

To finish the story, of course the rebooked flight was delayed by about an hour.