I don't think she has any legal authority to force Facebook to stop developing Libra. She probably does have the authority to subpoena Facebook executives to testify before her committee.
I also don't think there is a basis for being concerned that Facebook has a lot of data on its users, when discussing Libra. Most of what Facebook has access to is irrelevant to Libra, and banks have access to much more relevant information about their customers, especially their long standing customers, and they have access to information contained in third party databases such as credit reporting agencies.
The concept of a stablecoin is also not new, and stablecoins have had mainstream acceptance in the crypto space for years now.
There are a lot of reasons to be concerned about Facebook, but IMO libra is not one of them.
Yeah that'll be all. And even at that, Zuckerberg could (if he wanted to) fail to listen to the subpoena and just be held in contempt. I've seen little to no reaction from Congress when this happens anyway.
Even if he does speak in front of them, it's not going to mean anything anyway as Facebook is going to use their team of lawyers and lobbyists to make this work alongside the lobbyists of VISA, mastercard, etc.
Sounds like political BS / theater.
Zuckerberg could go to the committee hearings, and answer questions to the extent he knows the answers -- there is probably a lot that is still in the planning stages that is subject to possible change, so he may not be able to give a lot of firm answers.
Once Zuckerberg is at the committee hearing, there is nothing committee members can do to force him to put the development on hold, above public pressure.