If you’re not aware of Shodan, it is a search engine for IoT devices. It allows you to search across publicly accessible devices worldwide. You can use this to search your own network for exposed devices, or just dig around the internet looking for things. It’s a pretty interesting tool. It also includes and API for integration with nmap/metasploit/web browsers.
A standard membership is 49$ lifetime but this coming weekend will be down to 5$ (I also think you can get a free upgrade using an .edu account, don’t quote me on that).
Yes, we're having a black friday sale 🙂 $5 Shodan Membership instead of $49 and it will run from Friday through Monday
— Shodan (@shodanhq) November 21, 2017