In what ways Facebook could legitimize a request for telephone numbers? Answer: for security reasons. The information comes from TechCrunch, Facebook who confirmed that all members will be offered to fill this information. This would be a way to recover their account after a hack attempt, sending a new password by SMS. This process is supposed to be safer than the mail, sometimes considered as spam by users according to the blog of Cloudmark, a company specializing in the protection against spam including.
One can legitimately ask whether this argument represents an opportunity for the social network to get their hands on sensitive information: millions of phone numbers. The hostile reaction to this request should not be heard soon.
In response, the teams of Mark Zuckerberg will wield the recent fault LinkedIn 6.5 million whose passwords are in nature. In a similar case, it would suffice to Facebook to remove them quickly before sending new users by SMS. A strong argument that critics will hear.