Cool ... I'm a sucker for maps. I checked at 4:41 PM PDT (utc-7) and saw a _bunch_ of trains around London. What are all those people doing riding trains at 12:41 AM London time?_
[edit: added PM]
[edit: added PM]
This is fairly typical for commuter trains in general, really; a last train time of midnight to 1 am, resuming around 5am, is common. 24 hour commuter trains are relatively rare, as the volume isn't there and they tend to do track maintenance at night.