In case you're using Firefox on mobile - so myself and like four others - disabling Firefox' new Facebook data collection feature is quite a bit harder than on desktop, but it can be done:

1. Go to chrome://geckoview/content/config.xhtml
2. Use the search field to find the entry for aboutConfig and enable it
3. Go to about:config
4. Search for dom.private-attribution.submission.enabled and set it to false

Done. This only works on Android, because Firefox on iOS is just a Safari skin.