Wikipedia keeps track of official URLs for popular websites. With DNS over Wikipedia installed, domains ending with .idk are redirected by searching Wikipedia and extracting the relevant URL from the infobox.

Example:

1. Type scihub.idk/ in browser address bar
2. Observe redirect to https://sci-hub.tw (at the time of writing)

Instead of googling for the site, I google for the site's Wikipedia article ("schihub wiki") which usually has an up-to-date link to the site in the sidebar, whereas Google is forced to censor their results.

If you Google "Piratebay", the first search result is a fake "thepirate-bay.org" (with a dash) but the Wikipedia article lists the right one. — shpx