What was said that caused Facebook to shut down an AI system after chatbots started speaking in their own language ?

I’d like to know what the robots were talking about. Was it tonight’s lotto results? What do you think robots would chat about? Should arcane argot be axed?

https://yourstory.com/2017/07/facebook-shuts-ai-system-after-bots-create-own-language/

Days after Tesla CEO Elon Musk said that artificial intelligence (AI) was the biggest risk, Facebook has shut down one of its AI systems after chatbots started speaking in their own language defying the codes provided.
According to a report in Tech Times on Sunday, the social media giant had to pull the plug on the AI system that its researchers were working on “because things got out of hand”.