Microsoft's bot (Tay) learned as people talked with it. People took advantage of that and basically attacked it with racist things which meant it ended up learning to be a racist.
Thinking about it now, this is deeper... There's a fear that AI will take over the world, use weapons in unethical ways, say one thing and do another, etc... If we use news channel and politicians debates to teach AI, I'm afraid that this is exactly what we're going to get!
https://twitter.com/dorfsmay/status/785907475480350720
"The same way adults stop swearing once they have kids, we might become more honest and ethical by fear that AI will learn from us."
The core learning algorithms are not changing.