As part of its commitment, the app only stores mobile phone numbers, without names, emails and other personal info. But users were concerned that Facebook could either incorporate WhatsApp information into its own databases for advertising and marketing purposes, or start flogging ads to chatters on the IM app. The FTC said that it would be monitoring the companies' practices to ensure that Facebook and WhatsApp kept their word to users. The deal will still need regulatory approval in other regions, like Europe, before it can be finalised. ®