This is the first time I've ventured out of the MoR and Luminosity threads, and I support 5. If the limit was 1, spambots would eventually learn to post "Hey, I'm new" then wait a few hours before spamming.

Of course, this would also mean that no one should vote up a "Hey, I'm new" comment beyond 4.

Spambots would also create 5 siblings.