Your analogy doesn't hold. A 'hidden camera' would be either malware that does data exfiltration, or the company selling/training on your data outside of the bounds of its terms of service.
A more apt analogy would be someone recording you in public, or an outside camera pointed at your wide-open bedroom window.
We've got plenty of examples where Microsoft (owner of LinkedIn) is OK with spying on their users using methods akin to malware.
People who've put data on LinkedIn had some expectation of privacy at a certain point. But this is exactly why I deleted everything from LinkedIn, other than a bare minimum representation that links external to my personal site, after they were acquired.
Microsoft, Google, Meta, OpenAI... None of them should be trusted by anyone at this point. They've all lied and stolen user data. People have taken their own lives because of the legal retaliation for doing far less than these people hiding behind corporate logos that suck up any and all information because they've been entitled to not have to deal with consequences.
They've all broken their own ToS under an air of: OK for me, not for thee. So, yes, the hidden camera is a great analogy. All of these companies, and the people running them, are cancers in and on society.