That’s an interesting example. Some countries have laws that protect the sanctity of the confessional, but I think police in most countries could install a bug

That’s an interesting example. Some countries have laws that protect the sanctity of the confessional, but I think police in most countries could install a bug in there with an appropriate warrant (which hopefully wouldn’t be lightly issued). They can usually install bugs in your bedroom in a serious enough case, so there is no doubt that law enforcement does have a right to invade privacy. Even a regular search warrant obviously has the capacity to constitute a huge invasion of privacy.