system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 - why do trains care what you charge in their power sockets? Does it make a difference if i charge my laptop or my toothbrush?

I'm currently on a virgin train in the UK and they have a sign next to the power socket which reads "laptops and mobile phones only".
gpt
Laptops and mobile phones draw relatively less power than something like a hair dryer or electric space heater. If several passengers used such devices it is likely circuits would be overloaded and breakers popped. Passengers are dumb so they restrict it to a few examples.