Depending on how you do it and they find out, you could certainly be sued for fraud and misrepresentation, though. And, if you put a "copyright by me" at the to

Depending on how you do it and they find out, you could certainly be sued for fraud and misrepresentation, though. And, if you put a "copyright by me" at the top of a public domain work, it's technically a crime under 17 U.S.C. § 506(c) - Fraudulent Copyright Notice https://www.law.cornell.edu/uscode/text/17/506#c https://www.law.cornell.edu/uscode/text/17/506#c