[–] Stavon 0 points 1 point 1 point (+1|-0) ago
The best way sure is to handle both accounts and domains. Maybe Putt's banning tool can be improved to save him time.
Not preventing new accounts from commenting allows users to downvoat them into CCP restrictions though. Although that isn't done often enough and many spammers don't comment on their posts.
[–] AOU [S] 0 points 1 point 1 point (+1|-0) ago
The ones who do are "one-post" scripted spambots.
[–] Stavon 0 points 1 point 1 point (+1|-0) ago
Likely, those comments look all very similar.