When you have the Endless Scroll setting on and you mouse over the bottom 50px or so of the screen on your Tumblr dashboard, a footer pops up under your mouse with links to About, Meetups, Content Policy, ToS, etc. I find this annoying, because I end up being redirected to pages when I am really wanting to click a link in a post I'm reading, or just clicking on the page to focus the window, etc. All this script does is hide that footer from popping up.