Date of birth would be a bit harder to get. Not on the average bill or in a phone book. I guess someone could go through social media once they had your name, but it might not work for everyone.
I'm in the US. Online, I've obtained birth and death dates and lists of mailing addresses of specific persons. In one case, I started with the subject's name and county where they died (the goal was to find the burial plot of a relative). Other cases I started with a name and current city of residence (ie, googling myself and family members). I didn't search social networks. Iirc, most of my success came from online county records.