> I only give personal data to websites when I have to This is a great policy that I think more people should use. Not everything needs your real name, real bi

> I only give personal data to websites when I have to This is a great policy that I think more people should use. Not everything needs your real name, real birthday, or your real home address. Definitely not your real phone number. You often do need a real email address. > you don't usually need to give much personal data anyway This is where it gets tricky. Anonymized aggregate data can be surprisingly identifying. You only need 33 bits of information to uniquely identify any individual in the world. If your IP tells me you're from San Francisco, then I need just 20 bits of information to uniquely identify you. Data mining 20 yes/no answers about one of your users is ... pretty easy.