[ma2rten]

The post doesn't explain what shodan and censys are. Would anyone mind explaining it?

[ghostpepper]

They're websites that scan the entire internet to see which hosts are up and responding, and which ports are open, and then make the data available to researchers.

[achillean]

Here is a high-level explanation of Shodan and where it's used: https://help.shodan.io/the-basics/what-is-shodan