In countries that are signatories to the ECHR (European Convention on Human Rights) it is _sacred_, given it enshrines a right to privacy in Article 8 for some 800 million people. The Court is pretty judicially active in enforcing the rule as well, even in member states that have governments with crappy human rights records like Russia.

America and a few others are arguably outliers in the western world for failing to recognize privacy, and the right to private family life, as a fundamental right in some form of constitutional legislation.