Some doctors use copyright contracts to censor negative reviews →
https://marco.org/2011/05/30/doctors-claim-copyright-over-negative-reviews
The receptionist handed me a clipboard with forms to fill out. After the usual patient information form, there was a “mutual privacy agreement” that asked me to transfer ownership of any public commentary I might write in the future to Dr. Cirka.
The copyright claims may not stand up to scrutiny, but as with all intellectual-property matters in the U.S., most people can’t afford to fight any threats made against them.
Be careful what you sign.