First, while there's research on the math for things like ZNP, there is a shocking lack of research on security vulnerabilities for the actual implementations o

First, while there's research on the math for things like ZNP, there is a shocking lack of research on security vulnerabilities for the actual implementations of such age verification systems which should make anyone using them extremely nervous. Second, if a porn website, social media, video game or whatever other thing regulators want to discourage people visiting kicks you off into an age verification takes requires you to some system/site, even an independent one, that requires you upload your ID, a fair number of people will simply refuse simply due to lack of understanding in how it works and trust that it actually is anonymous. Third, every implementation I've seen doesn't work for some/all non-citizens/tourists. And finally and more importantly, the ease at bypassing those systems means it's unlikely to stop anyone underage and ultimately is no better than existing parental control software, so all one is doing is restricting speech for adults.