What is stealing copyrighted work by downloading or copying it called?

The act of stealing copyrighted work by downloading or copying it is referred to as piracy. This term specifically pertains to the unauthorized use and distribution of someone else's intellectual property, such as films, music, and software. Piracy is a legal violation that undermines the rights of creators and producers who rely on their work for income and recognition.

Counterfeiting generally involves creating imitation versions of products, often with the intent to deceive consumers about the authenticity of those products. Plagiarism, on the other hand, is the act of claiming another person’s work or ideas as one’s own without proper attribution, which may not always have a direct financial motive. Lastly, fraud encompasses any deceptive practice aimed at securing unfair or unlawful gain, but does not necessarily apply specifically to intellectual property theft. Therefore, piracy is the most accurate term for the act described in the question.