How did this hotel know that guest was sending illegal files on hotel network?

This article (from last March) describes a man arresting for sending child pornography over his hotel internet network.

How does a hotel know what’s being transmitted over its network? Do they monitor this? While I’m glad this guy was caught, I’m wondering if and how the hotel routinely monitors what guests do over their network.

WAG. The hotel might subscribe to a list of porn sites, SPAM sites, etc.

Also, hotels usually have disclaimers that the Internet access is not secure and may be subject to monitoring. If you frequent open access locations, unless you have a proper secure VPN connection, everything you are doing may be actively monitored and “sniffed.”

The files he sent were off his own computer. How are they able to read his transmitted files?

The cite says:

It sounds like he had OS level file sharing on, like a shared folder that showed up to anyone plugged in to the local network. A hotel employee or guest probably just saw the folder “No child porn in here” and opened it with guest access and reported it.

Unless they were sent over an encrypted connection, they can see and reconstruct anything that goes through their routers/switches if they want to.

But, yeah, it sounds like they didn’t even need to go to that trouble, since he made them visible to anyone on the network.