The Google Contacts team has announced that address book information from now onwards will start being displayed on your friends Google+ profiles, but only if you have them stored. For this you need not to add or remove any information on your end, since the details are completely populated from the Google Contact account visitors.
This is what Google Contacts team said:
Many of you, like me, use Google Contacts to manage your personal address book (contacts.google.com). If that’s the case, then starting today we’ll include this contact info on your friends’ Google+ profiles — for your eyes only, of course.
This way, if you have your roommate’s new phone number in Google Contacts, it’ll also be available when you stop by his profile. Just look for the new “Details from Google Contacts” section.