FB has already publicly announced some of these changes: https://www.inc.com/peter-roesler/facebook-to-allow-for-first-party-cookies-on-october-24th.html https

FB has already publicly announced some of these changes: https://www.inc.com/peter-roesler/facebook-to-allow-for-first-party-cookies-on-october-24th.html https://www.inc.com/peter-roesler/facebook-to-allow-for-firs... https://digiday.com/marketing/wtf-what-are-facebooks-first-party-cookies-pixel/ https://digiday.com/marketing/wtf-what-are-facebooks-first-p... Basically, FB is expanding its tracking, allowing 1st party vs. their third party cookie tracking. I suspect the click-id query string is part of that rollout. This helps it get around things like Apple's new ITP (Intelligent Tracking Prevention). 2.0 in Safari.