WhatsApp on Thursday announced an update to its terms and privacy policy -- the first in four years. Among other things, the changes will affect the ways users can communicate with businesses while continuing to avoid third-party banner ads or spam messages, according to the company. However, WhatsApp will begin to share some personal details about its 1 billion users -- such as phone numbers and other data -- with Facebook, its parent company. The information sharing will permit better tracking of basic metrics.