The world’s most widely used app-based instant-messaging service has made a change that is about to affect its one billion users.

WhatsApp, which was bought over by social media giant Facebook for $21.8 billion in 2014, is now going to share user information, including phone numbers, contact lists, and status messages with the social networking giant. At the time of its acquisition, WhatsApp had promised users that their privacy would be protected.

The company claims this is a positive move as it helps them coordinate better with Facebook, allow businesses of relevance to communicate with users through the social networking website, show users more pertinent advertisements on Facebook and get more accurate friend suggestions.

“By coordinating more with Facebook, we’ll be able to do things like track basic metrics about how often people use our services and better fight spam on WhatsApp,” the company wrote in a blog post. “And by connecting your phone number with Facebook’s systems, Facebook can offer better friend suggestions and show you more relevant ads if you have an account with them.”

WhatsApp reassured users that end-to-end encryption, which prevents any third party from decoding messages sent on the platform, will remain.

Wider net

This data-sharing arrangement is not just with Facebook, though. WhatsApp made it clear that user information may be shared with the Facebook “family” of companies, which could include other acquisitions such as photo-sharing app Instagram or virtual reality company Oculus Rift.

Facebook has been making strides in the instant messaging space with its own app-based messenger that no longer requires you to even have a Facebook account.

The data from WhatsApp could help the social media giant further monitor user preferences. Facebook already features targeted advertisements based on users' search behaviour. It can track their locations and let them know who on their friends' list are nearby.

The main beneficiaries of this will be companies that advertise on Facebook, even as WhatsApp said it is planning to test the feasibility of allowing businesses to send messages to their customers directly on its platform.

“You may receive flight status information for upcoming travel, a receipt for something you purchased, or a notification when a delivery will be made,” WhatsApp wrote in the FAQ section of its site. “Messages you may receive containing marketing could include an offer for something that might interest you.”

However, the company maintains that it does not like “spammy” advertising, so it will not feature banner ads. Moreover, user messages, photos and other media shared on the app remain safely encrypted, WhatsApp claimed, and said it is only sharing some information with Facebook.

Not much of a choice

Those who do not like these changes can either stop using the app or opt out within the next 30 days.

However, opting out will not mean that your information remains entirely private. As WhatsApp said on its website, “The Facebook family of companies will still receive and use this information for other purposes such as improving infrastructure and delivery systems, understanding how our services or theirs are used, securing systems, and fighting spam, abuse, or infringement activities.”

Effectively, the opt-out feature may only stop targeted advertising on users' feed while Facebook can still continue to access other details, such as usage data.

Facebook recently posted impressive gains owing to a soar in ad sales – its advertising revenue jumped 57 per cent in the first quarter of the year to $5.2bn (up from $3.3bn).

Market experts have said the company’s stock price has the potential to make a 20pc jump over the next year owing to rising advertising revenues on its properties such as Instagram – and potentially, WhatsApp.

Privacy concerns over WhatsApp use are not new – even though the company, in a welcome move, had introduced end-to-end encryption earlier this year.

There have been multiple hacking attacks on the platform since it was founded in 2009. Moreover, a Dutch University student developed a tool to prove that anyone’s personal information, including their profile picture, status messages and last-seen information (when they were last online on the app) could be accessed through WhatsApp, irrespective of what privacy settings they had chosen, because of a security flaw in the messaging service.

The latest decision to share information with Facebook puts into perspective just how much the social media giant is trying to learn about its current and potential users. There are also fears that despite all its assurances, WhatsApp will end up enabling spam with the introduction of marketing messages.

No way out

While the announcement has created a predictable amount of uproar regarding privacy concerns, WhatsApp is not the first app to be accessing or giving out information about you and it certainly is not the only one.

Internet giant Google has been hit with pretty much the same kind of allegations as Facebook: of collecting and storing data about its users through multiple platforms, including Gmail, Hangouts and other services, to offer better advertising to companies on its search engine. The only difference is that it does not advertise on social media platform – yet.

Similarly, many other communication apps, including Viber, Skype, Instagram and Snapchat, request permission to access a range of information – such as location, text messages, video and audio – at the time of installation, which theoretically allows them to collect a host of data from users’ phones.

Google’s Hangouts, an instant-messaging service, now integrates with users' offline SMS inbox, as does Facebook Messenger.

While there are alternative messaging apps such as Telegram that claim to be more secure and less invasive (though there are reports to the contrary) than Facebook and WhatsApp, the truth is that internet pretty much knows everything about users.

Just visit this Google dashboard that serves a nugget of what the search engine giant has learned about you. You can view your search and location history stored by the search giant here and here to see what your advertising profile looks like.

And now, WhatsApp’s move to share information with Facebook comes with an additional share of security and privacy concerns. Users are now wondering how exactly the social networking platform will non-intrusively monetise a platform that once emphatically stated that it will not do advertising and said in a blog post in June 2012:

“These days companies know literally everything about you, your friends, your interests, and they use it all to sell ads...“Remember, when advertising is involved you the user are the product.”

This piece originally appeared on Scroll.in and has been reproduced with permission.