[intorio]

Fair use only applies in certain contexts, of which writing commercial software is not one of. 'Snippets' are not fair use and it is shocking how many people here think they are.

[anon2020dot00]

People get snippets from Stack Overflow all the time and usually there is no concern whether it is properly attributed or not.

I'd argue that people who open-source code expect other people to learn from it in a small way of snippets and that constitutes fair-use.

[foldr]

Code in Stack Overflow answers is explicitly licensed under a permissive license:

https://stackoverflow.com/help/licensing

Copying code samples from a copyrighted work for use in a commercial product is not fair use.