@quinta wrote: "a on/off attribute attestation is absolutely not deanonymization"
1) Nothing online provides 100% reliability of identitity. An on/off attribute attestation definititely implies *partial* deanonymization - even if that is *seemingly* without risk.
2) Slippery slope: regardless whether the proponents want you to believe that they don't anticipate that fraud is too easy with just an on/off 18+ attribute, or they're really that naive: either way, more identifying attributes will be added soon.