Protecting them from commercial use of their personal data - without explicit consent. In the US it's more of a free-for-all and businesses can get away with much more; in EU countries, their governments prefer to protect their populations from businesses (before anything bad happens). Just a different philosophy.

That already is regulated in the EU, which has reasonable data protection legislation.

This is just supposed to be like the signs you are required to have if you use cctv, letting people avoid it if they wish to.