Shares of United plummeted 75 percent on the Nasdaq exchange today before trading was manually halted. All of this because of a chain of events that started when a link to an old story from 2002 on the air carrier’s bankruptcy appeared as a link on the website of the South Florida Sun-Sentinel, was picked up by Google News, got written up by a newsletter produced by Income Securities Advisor, which in turn was distributed on the Bloomberg wire.