By now those of you with Twitter have probably seen at least a tweet or two on AmazonFail. Basically Amazon employees delisted a bunch of books from their main search with homosexual content or characters by labeling them "Adult". The story was rapidly spread through Twitter by tweets tagged with the #AmazonFail tag.
There's a very rational account of the phenomenon from author Neil Gaiman, whose retweeting of the story certainly helped to boost its awareness. Notably he opines that it's really not clear whether this was an evil or simply stupid move on the part of Amazon/Amazon employees. It's such a huge company that it really could have been either one.
The power of Twitter and social networking is what's amazing about this story. Shortly after the resultant noise Amazon claimed the delisting was not deliberate but a "glitch" and took steps to list those books on their search again. Social networking was able to bring the outrage, the voice of these people, to the ears of such a huge corporation and effect change in an unpopular change. I think those looking for meaning and to define what Twitter and its purpose is have seen its a tool for political as well as commercial awareness.