I love how they just casually mention that they've been scanning the entire internet. It makes sense to me from a technical perspective, but quantifying the internet is still a pretty amazing thought in my mind.
Back when nmap first came out I used it to do something somewhat similar though on a much smaller scale. I was 15 or so and I did zone transfers on all the name servers listed in the file on Arins ftp site than scanned all the addresses I got back using nmap.
It was pretty interesting the results I got back though I had to stop when I was about 80% through the list as a sysadmin in California complained to my ISP and I was threatened with disconnection.
Of special note, Nmap 5.00 is now able to map IP addresses to AS numbers: "The script works by sending DNS TXT queries to a DNS server which in turn queries a third-party service provided by Team Cymru (team-cymru.org) using an in-addr.arpa style zone set up especially for use by Nmap.
The responses to these queries contain both Origin and Peer ASNs and their descriptions, displayed along with the BGP Prefix and Country Code."
Whoa, cool! Brings back memories from my IT admin internship days! I last used Nmap back in early 2000's after one of the programmers recommended it to me.
How is this not hacker news? Nmap is the port scanner / network security audit tool that everyone uses. It's a tested and true, classic piece of software.