Most of those people know how to use Tumblr responsibly and only post when they have something worthwhile to say. Others don't. First execution: Julia Allison. 40 posts a day? Are you f—-ing kidding?Executing friends is a great idea, Ricky! But what if you're like the New York Observer 's Doree Shafrir — yes, the writer who recently profiled Tumblr CEO David Karp — and you don't know how to stop following someone on the site? Never fear, Valleywag's here to help you knock off your most annoying friends.