Use Case: You see some author in a forum or in a blog that is not your contact, but you would like to add or contact this user.

Problem: There is no way to send direct messages or add the user remotely.

Possible Solution: Allow the user X to select a number of contacts that should be asked if they have this author Y as contact. Only if one of the contacts Z actually has the requested author Y, a notification/dialog is shown that informs the user Z that contact X wants to be introduced to Y with the option to either ignore this request or make the introduction.