It only takes one person in your entire contact list to upload their entire contact list, so that your information gets uploaded to Linkedin/Facebook/Google, etc. It's almost impossible to assert that level of control, so my assumption is that my details including my birthday, address, phone number, place of work, etc, has already been uploaded to all of those service. It's infuriating, but it's a reality since I can't stop one of my contacts from uploading my data.