Some lawmakers are already raising concerns about Facebook's plans to merge its messaging apps

Some lawmakers have spoken out about Facebook's plans to partially merge WhatsApp, Messenger, and Instagram.The social network plans to combine the back-end systems of the three apps, so users can talk to each other across platforms.But the move has faced early skepticism from some politicians, with concerns raised around data privacy and anti-trust issues.Facebook plans to partially combine its most popular messaging apps — and some lawmakers don't sound happy about it.On Friday, The New York Times broke the news that CEO Mark Zuckerberg is pushing his company to merge the back-end of Facebook Messenger, WhatsApp, and Instagram. The change would mean that users of one app would be able to message users of another, and it would tie the currently disparate Facebook-owned products far more closely together.The change comes as Facebook attempts to move on from months of bruising scandals and intense scrutiny over its handling of users' data, from Cambridge Analytica's misappropriation of more than 80 million users' info to Facebook's role spreading hate speech that fueled genocide in Myanmar.Against that backdrop, Facebook's latest messaging plans quickly raised fears that the controversy-plagued social network could become ever more powerful, and potentially dangerous. California Democratic congressman Ro Khanna was one of the first to comment, suggesting on Twitter that the move raised anti-trust concerns about Facebook's acquisitions of Instagram and WhatsApp in 2012 and 2014 respectively."This is why there should have been far more scrutiny during Facebook‘s acquisitions of Instagram and WhatsApp which now clearly seem like horizontal mergers that should have triggered antitrust scrutiny," he tweeted."Imagine how different the world would be if Facebook had to compete with Instagram and WhatsApp. That would have encouraged real competition that would have promoted privacy and benefited consumers."In an emailed statement, Democratic senator Ron Wyden, an outspoken voice on tech policy issues, told Business Insider he had concerns about privacy and data protection issues."I have a lot of questions about how Facebook intends to combine these services. If it does anything to weaken the security and encryption of WhatsApp, that would represent a major blow to the security of millions of people around the world," he wrote."If Facebook is doing this so it can harvest even more our personal information for profit, it’s yet another reason to be concerned about how corporations are using our data. This is yet another reason to pass a strong privacy bill, like the one Ive proposed."These comments from Capitol Hill may be more bark than bite for now. But with a growing call for tech regulation, and with several state attorney generals currently looking into practices of social media companies, Facebook can ill afford to give lawmakers another reason to scrutinize the company.The encryption wildcardAccording to The New York Times' report, Facebook plans to use end-to-end encryption across all three apps once the merger has taken place. It's not clear how it will work in practice, and spokesperson Jennifer Hakes declined to provide any information beyond a short statement. "We want to build the best messaging experiences we can; and people want messaging to be fast, simple, reliable and private," the statement reads. "We're working on making more of our messaging products end-to-end encrypted and considering ways to make it easier to reach friends and family across networks. As you would expect, there is a lot of discussion and debate as we begin the long process of figuring out all the details of how this will work."The criticisms are indicative of the immense skepticism Facebook now faces from many lawmakers and members of the general public, and the uphill struggle it will face to convince people that any changes it makes going forward have its users' best interests at heart.That said, not everyone is as pessimistic about the potential consequences of the move. Alex Stamos, the outspoken former head of Facebook's security, hailed it as having the potential to be "the most impactful uplift of communications privacy in human history.