Sorry, Mozilla doesn't track those who donate, so there's no way to block that message for those who have already donated. This fund raising campaign is entitled E-O-Y 2014 and should end soon after the New Year begins. If your issue is with the message displayed on the Firefox Start Page = about:home - you could temporarily set a different homepage until the campaign ends in a few days. See - [[How to set the home page]] Or you could use this User Style - https://userstyles.org/styles/104618/about-home-hide-snippets - to hide those messages.