What the Fallacy?! - Guilt by Association

What is it?

Attempting to discredit an idea or argument by associating it with an undesirable person or group.

Why is it bad?

Attempting to discredit a user by associating them with a banned person or 'blacklisted' server.

Example in Chat

@guilt_tripperToday at 6:30 PM

You can't trust his suggestion for the new server icon. I saw him chatting in the same public server as that guy who got banned for raiding last week.