Couldn't that have been done via a username like "anonymous923842748"? To me, upvoting accounts like this sets a concerning precedent for future impersonations, but I also agree with you that hiding the comment with a flag may not be good either. That said, I almost wanted to flag it as well just so others would see a lower reputation and not get confused about the real identity.

Maybe this is already a problem with accounts like @berniesanders, assuming this platform does take off to threaten the other major social media networks (think verified Twitter accounts). I'm curious how these issues will be resolved in a decentralized manner, but maybe that's a subject for a different conversation.