A German ISP tampered with their DNS – specifically to sabotage my website

Summary

One of Germany's biggest ISPs changed how their DNS works, right after I exposed an organization that they’re part of. My website: Publishing Germany's secret internet blocklist In Germany, we have the Clearingstelle Urheberrecht im Internet (CUII) - literally 'Copyright Clearinghouse for the Internet', a private organization that decides what websites to block, corporate interests rewriting our free internet. No judges, no transparency, just a bunch of ISPs and major copyright holders deciding what your eyes can see. I decided to create a website, cuiiliste.de, to find blocked domains, as the CUII refuses to publish such a list. To read more about the CUII, check out one of my previous blog posts. Germany's four biggest ISPs (Telekom, Vodafone, 1&1 and Telefonica (o2)) are all part of the CUII. Yet another slip-up by the CUII This week, Netzpolitik.org published an article about the CUII's latest blunder, based on information I gathered. They managed to block domains that no longer even existed: websites that had already been seized and taken offline when they were blocked. It's not the first time the CUII has tripped over its own feet, and this mistake likely didn’t sit well with them. In the past, it was really easy to find out if a domain was blocked by the CUII. If you asked an ISP's DNS server (basically the internet's phone book) for a site and got a CNAME to notice.cuii.info, you knew it was blocked. What this basically means in case you're not a tech nerd: You can check the phone book of an ISP (the "DNS server") where to find a website, and you'd receive a note saying "This site is blocked by the CUII" if the page is blocked. Automating this was simple, I could basically just ask "Hey, where can I find this site?" and immediately knew if it was blocked. The CUII apparently did not like the fact that it was so easy for me to check if a domain was blocked. They want to keep their list secret. ISPs like Telekom, 1&1 and Vodafone actually all stopped using thi...