Never was in modern sense. It's invention of corporations to have enormous amounts of money for nothing.

The only thing wrong with plagiarism is pretending you made it yourself. Copy and give credit.

There is no such thing as intellectual property outside of stuff you keep secret. Once you put it out in public it is no longer property. It’s plagiarism when you claim to be the original creator of the exact thought and you’re not. Plagiarism is an academic/reputation/moral issue, not a crim...

Thanks !