Arguably the face of Facebook, CEO Mark Zuckerberg, will be heading back to the Hill, this time to testify on Facebook's proposed Libra digital currency and Calibra digital wallet to hold that digital currency. 

The house Financial Services Committee, chaired by Maxine Waters (D-Calif.), announced the Facebook founder would be the lone witness at an Oct. 23 hearing tabbed: “An Examination of Facebook and Its Impact on the Financial Services and Housing Sectors.”  

Zuckerberg's appearance follows a letter Waters and committee Democrats sent to him in July calling for a moratorium on the cryptocurrency and wallet, which Facebook had announced a month earlier. "[T]he scant information provided about the intent, roles, potential use, and security of the Libra and Calibra," they wrote at the time, "exposes the massive scale of the risks and the lack of clear regulatory protections." 

Related: Sources: Senate Commerce Slates Oct. 23 STELAR Hearing 

They wanted Facebook to hold off until Congress could examine those issues. But they did more than just warn the company. 

Waters held a July hearing, “Examining Facebook’s Proposed Cryptocurrency and Its Impact on Consumers, Investors, and the American Financial System,” with Calibra's CEO to discuss a bill they had drafted, the Keep Big Tech Out of Finance Act, which would effectively bar Facebook from launching Libra and Calibra by "prohibit[ing] large platform utilities from establishing, maintaining, or operating a digital asset that is intended to be widely used as medium of exchange, unit of account, store of value, or any other similar function as defined by the Federal Reserve." 

The term "utilities" could not have been pleasing to social media companies, since the government gets to regulate utilities heavily. 

"Libra is already falling apart at the seams," said Freedom from Facebook co-chairs Sarah Miller and David Segal. "There’s growing realization that the objective of Zuckerberg’s private financial system is not to provide any sort of benefit to the public, but to entrench Facebook’s power-- which is already causing partners like PayPal to walk away. Congress’ aggressive scrutiny of the project is well-warranted. It’s important that they keep pressing on key concerns about systemic risk, economic and political power, and privacy. In doing so, they’ll ensure Libra never gets off the ground."