Few works are released directly to the public domain. It is my understanding that the public domain doesn't even exist in all legal jurisdictions.

Most people license out the software under specific requirements and prohibitions. BSD requires attribution. GPL variants require adherence to copyleft when distributing derivative works. A little under half of all github repos don't even have a license, which means that though the source is published, no one has any license under which to copy it or derive new works from it.

So far as I have seen, whether aggregating and munging these works into abstract LLM weights constitutes fair use is still legally unclear. If not deemed fair use, it is almost certainly a massive violation of copyright.

Worth noting that the ai giants 'stole' from open source, but they also stole from closed source.

That is, they knowingly and willingly broke the law by stealing an unprecedented volume of proprietary, copyrighted materials.

Books: Bartz v. Anthropic

Films and TV: Disney Enterprises Inc. v. Midjourney Inc.

Music: Concord Music Group, Inc. v. Anthropic

Photography: Getty Images v Stability AI

Journalism: Postmedia Network Inc., Torstar Corporation, The Globe and Mail Inc., and The Canadian Press v. Anthropic PBC

Doesn't this impl that licensing was respected? I feel like it wasn't

That's as noble as throwing breads at the crowd while being perfectly aware that there lurks a number of armed henchmmen of "noblety" in it, who won't miss the opportunity to amass those breads to resell them.

Or at least just childishly naive for failing to notice that beforehand.

Speak for yourself. I don't see every model being released under GPL after having read the entire source code as a step of creating their binary artifacts (model files).

The point of the open source I work on is to contribute to a commons, not to have it stolen so that it can be used to destroy those commons, used for the profit of techbros, and used to justify the murder of children.