(Pocket-lint) - After the news broke yesterday that Facebook could be broken up by the US regulator, the social network has hit back in a blog post. 

Specifically, the Federal Trade Commission (FTC) seems to be seeking to force the spin-off of Instagram and WhatsApp - despite having approved those transactions in 2012 and 2014 when both Instagram and WhatsApp were much smaller entities. Additionally, the WhatsApp transaction was also checked by the European Commission, too.

Jennifer Newstead, vice president and general counsel at Facebook says of the move by the FTC:  "Now, many years later, with seemingly no regard for settled law or the consequences to innovation and investment, the agency is saying it got it wrong and wants a do-over. In addition to being revisionist history, this is simply not how the antitrust laws are supposed to work.

"No American antitrust enforcer has ever brought a case like this before, and for good reason. The FTC and states stood by for years while Facebook invested billions of dollars and millions of hours to make Instagram and WhatsApp into the apps that users enjoy today. And, notably, two FTC commissioners voted against the action that the FTC has taken today."

Strong words indeed. Newstead also argues that Facebook does have strong competition: "We constantly evolve, innovate and invest in better experiences for people against world-class competitors like Apple, Google, Twitter, Snap, Amazon, TikTok and Microsoft. We innovate and improve constantly because we have to.  

"We face competition in every aspect of our business. That was true before the acquisitions of Instagram and WhatsApp and remains true today. With so many rivals, our customers can at any time choose to move to another product or service — and sometimes they do. The lawsuits ignore this reality."

Newstead also makes the good point that Instagram has been completely powered up by Facebook: "When Facebook bought Instagram, it had about 2% of the users it has today, just 13 employees, no revenue and virtually no infrastructure of its own." While the post also tries to draw this parallel with WhatsApp, the effect has not been quite so drastic although you couldn't argue that it's the same entity Facebook bought in 2014. 

Writing by Dan Grabham.