Stories have shown up in several news outlets over the past couple days about, as the Associated Press says, “a movement of Christians loosely organized by radio broadcasts and websites, independent of churches and convinced by their reading of the Bible that the end of the world will begin May 21, 2011.”

The San Francisco Chronicle writes that a leading voice in that movement is Harold Camping, who runs the Family Radio evangelical station “that reaches listeners around the world.”

Camping once thought that Judgment Day (when some say believers will be taken to heaven and others will be left on earth for about five months of torment) would come on Sept. 6, 1994. According to the Chronicle, “Camping allowed that he may have made a mathematical error. He spent the next decade running new calculations [based on his reading of the bible], as well as overseeing a media company that has grown significantly in size and reach.”

Now, thanks to the Internet age, word about May 21 is being spread via the Web.

And, as you can see in the photo with this post, some are advertising their belief on billboards, RVs and cars. Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.