US Airways accidentally tweeted a pornographic photo in response to a user complaining about them about a bad experience.
A little back story for ya. A random twitter user sent the lewd photo to the US Airways official twitter account, and wanting to report the image, they copied the link to send to twitter to get it removed. Then, when attempting to reply to the complaint, they "accidentally" sent out the same pornographic link to the complaining customer.
I'm not going to post the photo, or link you to the photo. But trust me, it's bad. Read more about the incident here.
This isn't the first time a company has screwed up via twitter. Lots of blunders have occured, and you can read more about a few of those here.