I believe that those privacy issues are mainly connected to info supplied while registering for a product and some advertising. Even it's been reported that some chain stores are sharing customers' personal info with business partners. It's always good to read website stores' privacy policy.
As suggested by Malwarebytes, we should all limit our email and home address info to known well established businesses (stores, websites etc)
Here is an interesting article on home address security and internet:
Hide your home address from websites and profiles with our expert guide.
www.cnet.com
I seldom register a new product with a manufacturer. In Quebec, the law protects us for manufacturer's warranty, so we don't need to register a product bought in Canada..