When it comes to the internet, tech is law. There is no way to publicly share something and maintain control over it. Even on the Fediverse, if either a client or server wants to ignore part of the protocol or model, it can. Like a system message to delete particular posts for anti-surveillance reasons can simply be ignored by any servers or clients that were designed/modified for surveillance. Ultimately the buck lies with the owner of some given data to not share that data in the first place if there's a chance of misuse.