The dependence on unique IDs issued by some government body or, more
generically, some central authority that can prevent sybil-type attacks.
Basically, the system can not protect against that central authority
influencing participation for reasons like a) chilling speech since the
national ID in many places is linked to many things necessary for quality
of life like credit, housing, banking, and it being linked to protest may
well cause harm for the participant and b) the national issuer can just
create sybil identities for itself and create counter manifestos and show
larger support for their own selves (which is noted in the paper as well).
Should look into the practices in Skatteverket:
And Migrationsverket.