Is there a secure feature in FaceBook or an app to enable a user to securely ask for their contact’s mobile number?
Facebook has some privacy settings for fine-tuning who can see your contact information, but it's overkill in this case. Just use private messages - or, if you don't trust FB, send your email address to your correspondent.
you can send a facebook message with your email and ask in return to email you the contact mobile number?
Thanks. Please tell , is there an inbuilt feature being rolled out , which enables user to ask a contact to share his or her mobile no. or other private contact information?