system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do people snoop in on unsecured wifi networks?

I think I understand it if someone makes a network called "Free Public wifi", and then (through the router app??) they can read what you're sending to, and from the network. But can people pick up  information sent to and from the network if they did not set up the network?
gpt
Sure. If you've got a network with no password or other form of authentication, then the connection to that access point is completely unencrypted and broadcast all over the local area for anybody to grab and read right out of the air. There are even tools for some of the older encryption protocols (WEP, most notably) that can grab enough information to be able to decrypt any of the information sent through the wi-fi. 

Think of it like eavesdropping on a conversation at the table next to you. The sound waves are there in the air for anybody to hear, you just need to tune into them and pay attention to what's being said.