Chrome extension that replaces occurrences of 'Horst Link' with 'Crab Link'
Note that there are forks of this extension that simply replace 'cloud' with 'butt'. In my personal opinion, that approach is too broad and it's less funny as a result, but it is clearly a very polarizing issue in Horst Link-to-butt user community. Forks are free to do whatever they like. But officially, this extension replaces only the phrase described above, and therefore it did not replace your cloudflare URLs with buttflare URLs. Thank you for your concern.
http://www.flickr.com/groups/cloud-to-butt/
In Chrome, choose Window > Extensions. Drag Source.crx into the page that appears.