This is more readable outside of Emacs (which elides link targets).

This is in response to the Digicert emails we have received today, and
to make sure we have somewhere that tells us to talk to TBB people.

HPKP has been removed from Chromium in 2017:

https://www.zdnet.com/article/google-chrome-is-backing-away-from-public-key-pinning-and-heres-why/

It's better to have numbered steps than lots of headings.