Privacy groups have filed a complaint with the Federal Trade Commission protesting Facebook’s recent $19 billion deal to purchase messaging service WhatsApp.

The Electronic Privacy Information Center and The Center For Digital Democracy have argued that Facebook’s activities in sharing user information with advertisers will continue with WhatsApp, which handles more than 450 million monthly active users. In the complaint, the organizations claimed that the proposed acquisition could lead to “unfair and deceptive trade practice.”

Expect some response from Facebook regarding the privacy complaint. Monitor the acquisition as it goes forward, and after it has closed, to see what, if any, changes are made to WhatsApp’s terms of service regarding user information.

Facebook announced its acquisition of WhatsApp on Feb. 19. At that time, WhatsApp cofounder Jan Koum reeassured users that “nothing” would change.

Privacy groups voice skepticism over Facebook’s $19 billion WhatsApp deal.

“WhatsApp will remain autonomous and operate independently,” Koum wrote in a blog post. “You can still count on absolutely no ads interrupting your communication. There would have been no partnership between our two companies if we had to compromise on the core principles that will always define our company, our vision and our product.”

Despite these statements, the complaint noted that “Facebook routinely makes use of user information for advertising purposes and has made clear that it intends to incorporate the data of WhatsApp users into the user profiling business model.”

WhatsApp processes as many as 50 billion messages per day. Its privacy policy states that names, emails, addresses and contact information are not collected, or sold for advertising or marketing purposes. Undelivered messages are deleted after 30 days of inactivity. In contrast, Facebook’s Messenger app stores messages even after they have been deleted, and tracks content entered into the app even when it has not been sent.

According to Facebook, WhatsApp’s core messaging product and Facebook’s Messenger app will continue to operate as “stand-alone applications.” However, prior to its acquisition by Facebook in 2012, Instagram promised users that information would not be used for advertising, the complaint noted. Following the acquisition, Facebook “did in fact access Instagram users’ data,” and changed its terms of service as a result. Like Instagram, WhatsApp has a provision in its terms of service that user information and content could be “sold or transferred” following any acquisition.

The filing makes the case that by promising privacy protections, but failing to disclose that these protections could be taken away, WhatsApp’s lack of disclosure constitutes a deceptive practice. Further, even though Facebook is known for its data collection practices, WhatsApp did not and has not taken measures to protect user data collected pre-acquisition from the possibility that it could be accessed post-acquisition.

The complainants request that the court investigate the acquisition and halt further activity on the merger until the above issues are resolved. If the acquisition goes forward, they request that Facebook be ordered to prevent WhatsApp user info from being accessed by Facebook itself.