Microsoft this week launched the experiment in which the bot nicknamed "Tay" was given the personality of a teenager and designed to learn from online exchanges with real people.
An "automated lawyer" chatbot service has successfully challenged and overturned more than $2.5m in parking tickets in New York and London, according to its inventor.
The Do Not Pay service automatically generates an appeal if people fit the criteria to challenge a parking ticket – all using publicly available information – and it has been successful an extraordinary 64 per cent of the time, says London-born Stanford student Joshua Browder.
In hard numbers, that's 160,000 times out of 250,000 seen. Parking tickets are a multimillion dollar industry.
But it got a harsh lesson in what it can learn from people.
As a result, Tay was taken offline for adjustments to the software, according to Microsoft.
"C U soon humans need sleep now so many conversations today," Tay said in its final post on Twitter.
All the offensive Twitter posts by Tay were removed, but many echoed online in the form of captured screen shots.
Tay tweets ranged from support for Nazis and Donald Trump to sexual comments and insults aimed at women and blacks.
Tay's profile at Twitter describes it as AI (artificial intelligence) "that's got zero chill" and gets smarter as people talk to it.
People could chat with Tay at Twitter and other messaging platforms, and even send the software digital photos for comment.
The project was said to target young adults with chatter styled after a teenage girl.