Imgflip has the ability to take action against accounts that break the Terms of Use. Most users don't actually read the whole thing and miss a lot of important things there.
Since alt accounts and their main accounts continue to cause problems based on Stream Rules, suggest Stream Owners can consider post and comment bans for the main accounts and their admitted alts too.
One of the problems with Stream Moderators having access to the Ban feature is they may not have the overall Stream goals as their basis for banning, for example exempting their own alt account(s) while banning other user's alt account(s).
IMO Imgflip should give Stream Owners a switch that controls whether Stream Moderators have access to the Ban feature.