The Federal Trade Commission isn't too happy with Fcaebook's aquisition of WhatsApp, but it grudgingly approved the deal on Thursday after issuing a very strong warning. Facebook must maintain the high privacy standards of WhatsApp and be transparent with users about any changes in policy.

Jessica Rich, director of the FTC's Bureau of Consumer Protection issued a letter, warning both Facebook and WhatsApp that the FTC will be watching their every move to ensure that users' privacy expectations continue to be met. 

"Hundreds of millions of users have entrusted their personal information to WhatsApp," the regulator said in a letter to EPIC, one of the campaign groups that lodged a complaint about the takeover's implications. "The FTC staff will continue to monitor the companies' practices to ensure that Facebook and WhatsApp honor the promises they have made to those users."

In the letter, the FTC also made it clear that Facebook and WhatsApp must alert their users of any and all changes made to privacy policies as well as data collection.

"Before changing WhatsApp's privacy practices in connection with, or following, any acquisition, you must take steps to ensure that you are not in violation of the law or the FTC's order," the letter read.

Ever since the deal was announced early this year, WhatsApp and Facebook have had to defend the deal. Both companies have worked hard to allay privacy concerns and promise that this time around, Facebook will behave differently.

"Respect for your privacy is coded into our DNA, and we built WhatsApp around the goal of knowing as little about you as possible," WhatsApp founder Jan Koum said in a blog post shortly after the sale was announced.

Facebook also issued a statement after the purchase of WhatsApp in hopes of dispelling misinformation about Facebook's intentions for the popular messaging app.

"We are absolutely not going to change plans around WhatsApp and the way it uses user data. WhatsApp is going to operate completely autonomously," Mark Zuckerberg said in February, shortly after the deal was announced. "They might use people and infrastructure to grow, but the vision is to keep the service exactly the same. They do not keep the content you send, and we're not going to change that." 

In spite of all the assurances from Facebook and WhatsApp, users and the FTC remain suspicious of the deal.