How long will the 16 digit code last for? How truly anonymous are those codes? If my code is leaked will it be possible to view all of my porn viewing activity?

How long will the 16 digit code last for? How truly anonymous are those codes? If my code is leaked will it be possible to view all of my porn viewing activity? Why is reporting on this so terrible? I actually don't have a problem with requiring age restrictions on certain content online I just have no confidence that it will be implemented securely and anonymously when there are no competent journalists to hold politicians to a high standard.