Ira Glass, radio host of The American Life, explains in a blog post:

I have difficult news. We've learned that Mike Daisey's story about Apple in China - which we broadcast in January - contained significant fabrications. We're retracting the story because we can’t vouch for its truth. This is not a story we commissioned. It was an excerpt of Mike Daisey's acclaimed one-man show "The Agony and the Ecstasy of Steve Jobs," in which he talks about visiting a factory in China that makes iPhones and other Apple products. The China correspondent for the public radio show Marketplace tracked down the interpreter that Daisey hired when he visited Shenzhen China. The interpreter disputed much of what Daisey has been saying on stage and on our show. On this week's episode of This American Life, we will devote the entire hour to detailing the errors in "Mr. Daisey Goes to the Apple Factory." Daisey lied to me and to This American Life producer Brian Reed during the fact checking we did on the story, before it was broadcast. That doesn't excuse the fact that we never should've put this on the air. In the end, this was our mistake.

If you are trying to denounce something important, make sure you’re clean. Do not invent to make the story look bad. Worse make sure you really experienced what you claim to have, because, when people find out, they’ll feel betrayed. They probably trusted your story and maybe spread your ideas. How do they look like now? They look like fools.

As a result, your credibility as the source of these ideas will take a serious hit. The cause you were fighting for will lose its value since based on lies.