Libra would:
Centralize corporate control by giving Facebook more power, undermining sovereign states and giving the corporate interests behind the project the ability to distort global currencies or undermine governments at will.
Promote tax dodging and money laundering by making it easier for people to hide their money in a new network with global reach.
Erode freedom with no clear limits on Facebook's ability to use data from Libra purchases, bake racist discrimination into its algorithms, change the rules in the future or demand that employees take payment in currency it controls.
Put consumers at risk with none of the guarantees, oversight and protections found in traditional banking.