You have a constitutional right to privacy from the government. There is no such constitutional right (in the U.S.) that would prevent private surveillance, especially in cases where it is consensual.
At least in US law, it is incumbent on the parties of a contract to understand it. If they sign without understanding, that’s on them. Terms of use are a contract between you and a website owner. If you don’t understand them, you can either not use the website, or accept the risk that you’re consenting to something you may not like. (Again, this is the current state in the U.S. I’m aware it’s different elsewhere.)