This is a userscript that automatically validates the cyclical linkage of rel=me links on the pages you visit. It happens entirely from your browser, no third party server is needed. The script will request permission to access the entire internet the first time it tries to verify a link (tested in Tampermonkey for Chrome).
The script tries very hard to not interfere with the layout of the page, by making the verification markers float at the top left of the links. This may not always be 100% successful.
Inspired by indieweb/verify-me.