How ironic: Twitter’s stock plunged 18% today because of a tweet. The company was supposed to announce earnings after the close of the market, but the website Selerity tweeted them beforehand, reports the Wall Street Journal. It was bad news: First-quarter revenue was $436 million, about $20 million below estimates, and shares tumbled instantly. Trading was even halted temporarily following the early release of results. Twitter also warned investors that second-quarter revenue will be lower than expected.