Chipotle's Twitter account seemed to have been taken over this week by someone seeking tips on where to buy avocados, but the company says the bizarre episode was a deliberate PR stunt. The apparent hacking dovetailed with an online scavenger hunt that asked people to find recipes for guacamole, spokesman Chris Arnold says. "The idea was to do something with our social media that would get people talking. ... This is far more hoax than hack," he says.