When you have wit of your own, it's a pleasure to credit other people for theirs.

That person is a failure who steals the science of a scientist and claims that he is the owner.

That would be a copyright infringement.

Kill Piracy; Save Creativity

Footnoting references, signalling quotations, and so on were no part of a 13th-century scholar's duty. He could recycle his own and his predecessor's work without a qualm. He knew nothing of copyright and plagiarism, which are 17th-century inventions.

People who copy you will always be one step behind.