I noticed myself and in the comments of higher-rep users that we seem to have a certain user (who keeps registering new usernames, i.e. "sockpuppets") and keeps asking questions about genes and beauty/attractiveness, usually with pictures of ugly and attractive people attached, as if illustration is really needed.
Is there some guideline for dealing with such? I guess "ignore" would be the received rule...
Downvote liberally, close if appropriate, and flag if appropriate (as you would for any other post).
The most recent post, per the comments, had a link that led to a stuffed browser history. I originally flagged for moderator attention, but then realized that I could just edit out the offending link. I think the user could use some moderator attention, because, though the post is no longer concerning, I think the behavior is. Best case, it represents either an effort to prank other users, or, if accidental, a lack of care.
As to whether this is a sockpuppet issue, I'm not sure it is. There is a specific internet subculture that becomes quite fixated on these sorts of things, so it's plausible that these questions could be coming from different users.
Always flag suspicious sock puppets so that the mod team can look into it. Mods have tools to cross-check users and identify such users. In fact, using multiple sign-ins, although not recommended, is not a problem. Problem arises when users ask the same questions or otherwise perform repeated misbehavior with them.
