Allowing users to Opt-in or Opt-out of sharing their contact information when registering for a mtg

We host some calls given by companies outside our membership roster. Some members would prefer we not share their contact information with the Host. Is there a way for attendees to register for a call but opt-out or opt-in in allowing their contact information to be shared? I've seen the article on Changing your name when logging in but I don't know if that also restricts all sharing of your data.

Much appreciated, Eric