Prevents Google Chrome (and maybe other browsers) from scraping your passwords and sending it to their "spellcheck" servers

Keep-Passwords-Private.user.css

/*
@name             Keep-Passwords-Private
@namespace        e-t-l
@homepage         https://gist.github.com/e-t-l/443a88820bad69c0f82691fecdfd02a4
@match            *://*/*
@version          1.0
@author           e-t-l
@license          CC0-1.0
*/

/*
==UserStyle==
@name             Keep-Passwords-Private
@namespace        e-t-l
@homepage         https://gist.github.com/e-t-l/443a88820bad69c0f82691fecdfd02a4
@match            *://*/*
@version          1.0
@author           e-t-l
@license          CC0-1.0
==/UserStyle==
*/

input[type="password"] {
  spellcheck: false !important;
}