Facebook is facing yet more scrutiny from data-protection regulators in Europe following policy changes that will allow data from its free messaging service WhatsApp to be used for advertising. European Union regulators on Monday reacted to the changes by stressing that European users need to remain in charge of their personal data. Italian and British privacy authorities said they will also probe the changes WhatsApp and Facebook have planned.

"Privacy-policy changes are followed with extreme vigilance" by EU and national data-protection regulators, the Article 29 Working Party, made up of the EU?s 28 privacy chiefs, said in a statement on Monday. "What?s key is that the individual keeps control over his data when these are combined by the big Internet players."

WhatsApp?s changes are the first steps by Facebook toward monetizing the platform since the social network?s chief executive officer, Mark Zuckerberg, paid $22 billion for the app in 2014. The transaction at the time already raised concerns with European regulators about the collection of data from people?s contacts. A Dutch probe was closed last year after WhatsApp addressed all concerns.

WhatsApp said in a statement on Monday that it "complies with applicable laws" and that
it has made its "privacy policy easily accessible, provided an overview of the key updates, and empowered people to make decisions that are right for them, including offering a control for existing users over how their data can be
used."

WhatsApp had said on Aug. 25 that its users' "encrypted messages stay private and no one else can read them. Not WhatsApp, not Facebook, nor anyone else" and that they "won?t post or share your WhatsApp number with others, including on Facebook, and we still won?t sell, share, or give your phone number to advertisers."

What the changes will do would be to connect users? phone numbers with Facebook?s systems and allow it to "offer better friend suggestions and show you more relevant ads if you have an account with them."