aiweirdness:

An Etsy programmer trained Markov chatbot versions of some former coworkers, and then when people grew tired of them, moved them to a private chat channel where they could continue to post messages to each other.

Unattended:
1. The chatbots continued repeating commands that the Etsy employees had used including
2. Inviting the command-executing bot into the chat, which then
3. Started executing their commands
but
4. Although they could have given commands to kill processes and take down servers their commands were all to give their friends kudos

The potentially highly destructive bug was discovered when one of the bots’s friends, who happened to be a current real employee, mysteriously obtained 30,000 kudos overnight.

Source