Sovereign monetary policy goes out the window if Libra takes a serious hold in society. The only solution to that is a decisive ban on it.
When reading a lot of these arguments, a lot of them seem to me to be very “white box” defending the end result against legislation by arguing about the internal implementation.
Facebook is creating a financial instrument. I’m a bit surprised regulators couldn’t use _existing_ legislation to prevent them from using it in a country.
The financial instrument part of it is getting all the attention here even though it's hardly essential to Libra (the platform as a whole). That too is not new and they'd have to apply existing legislation in a way that is consistent with how they are already applying it.
That's the key point. Failing to do that would create a lot of problems; which automatically translates into court cases and judges deciding on what is the correct way to do this rather than politicians. That will take many years. Existing legislation is the only legislation that matters because creating new laws or emergency laws would be very hard; especially considering that nobody seems to agree on what should actually be in those laws.
So we're getting a vague "we don't like that sort of thing" in response to a deliberately vague press release a few months ago that wasn't being very specific on a lot of things. It's a political statement not actually backed up by concrete plans to change legislation or instruct authorities to interpret it in a certain way. It's a hollow threat.
Of course you have to see this in the context of the bigger picture of tax dodging and privacy violations associated with big US tech companies operating in Europe and the public pressure to do something about that. That's what this is. Political posturing.
France and Germany are being quite vague about what exactly they will block, what the scope is of that, or even how they imagine this would work. Also, Facebook itself has not been very clear about their actual intentions or those of the Libra legal entity that is supposedly governing all of this. Depending on how you read their announcements, Libra the coin might be considered as an experimental/optional part of an overall solution or vision that could also involve euro/dollar tokens (just like others trade on Stellar, Ripple, etc.).