Recently Apple has started scanning all the photos users have on their devices to detect possible child abuse, other corporations are already scanning all the content uploaded to the cloud. Therefore, without asking anyone, they have taken the responsibility to act as a private police on an international scale.
If people accept the principle, then how can they prevent those corporations from using the same mechanism to discreetly scan for political opinions? Can a limit to the police like duties taken by the corporation be imposed in a legal manner? I am not interested in legal approaches that could be taken in the US because this is the country of those corporations, I am interested in what could be done legally in other countries that find themselves subject to the action of foreign private police forces.
Related question: https://law.stackexchange.com/questions/71285/is-apple-scanning-user-content-for-child-abuse-a-violation-of-gdpr