[mindslight]

> can be used to construct something that confers greater privileges in other contexts

Then this wouldn't be zero knowledge, as it would convey whatever other greater information is available in that other context.

Are you perhaps thinking of the ecash double spending protocols? Where by double spending the same token to two different receivers, you leak enough information for your bank to recover your identity? That wouldn't be applicable here since each token would only be used once, there would just be many generated to share.