Trayvon Martin’s shooter George Zimmerman has not yet been charged with a crime, but with the aid of a sensationalist media and racial agitators like Al Sharpton, he has already been tried and found guilty in the court of public opinion. Now, the hate-filled public lynch mob wants him dead, too. The Internet now teems with death threats against Zimmerman, many of them explicit. A Twitter account called “KillZimmerman” has been active for nearly a week. The page shows a mug shot of Zimmerman, a bull’s-eye around his head, and reads: “This Page Is 4 Da Ppl Who Believe Zimmerman...