Ah, I had no idea that was protected too! That's good. I think the reason I was morally on the fence was that people already put blog posts out with the intent of sharing their knowledge with the rest of the Internet...
So my assumption was that anything trained on it will just help further expand that knowledge.
Although I do realise now as I'm typing this—AI could diminish their audience, clout and motivation, which isn't what I'd want.
In order for blog posts (or other written works) to be in the public domain, authors must explicitly waive those rights. But, not that it needs saying, copyright's applicability in training data is basically the entire subject of debate right now. https://creativecommons.org/2023/02/17/fair-use-training-gen...