How to Disable Pocket Integration in Firefox
To disable the built-in Pocket stuff in Firefox, do the following:
1.Type about:config in the browser’s address bar and hit the Enter-key. Confirm that ‘you will be careful’ yadda yadda.
2. Search for browser.pocket.enabled. Double-click on the preference to toggle its state from true to false.
How to disable Pocket in Firefox | Ghacks