Yeah I considered that - but any friction is better than none. Maybe integrate an additional consideration by which low karma (threshold < 5 karma) accounts cannot upvote other low karma accounts.

Honestly, we don’t really have the same cold start problem that a brand new social media site would. We already have plenty of reputable active users here. So HN could restrict new accounts to only being able to comment initially. As they participate, their comments receive upvotes, allowing them to build up enough karma (even a small amount of 25) which unlocks the ability to upvote, and then, finally, the ability to create posts.