Do not allow newly created accounts to create new threads

For the past couple of days I see that there are advertisements being submitted to HN. For example. http://news.ycombinator.com/item?id=523061 http://news.ycombinator.com/item?id=523001 And the accounts through which these threads are submitted are just created (2 hours and 1 day in the above cases). I thought we can prevent this by not allowing user accounts created within a couple of days to create new threads or by not allowing user accounts with 0 or lesser karma to create new threads. Any thoughts ?

These attacks are probably automated, and it would be trivial for the spamming software to be updated to get round these restrictions. I don't think it would take long.

The cost would be that HN would be less welcoming to newcomers.

That's a permanent loss for temporary gain, and I don't think it's worth it.

I think your idea can be improved on:

(a) instead of hardcoding conditions that we think indicate spamminess, the server should be keeping track of what characteristics spammers tend to display (sprinkle Bayesian magic pixie fairy dust here)

(b) new threads that are neither clearly spammy (banned) nor clearly unspammy (allowed on as now) should be provisionally allowed on the new page, but then banned should a single reader flag it, without the intervention of a moderator

(c) moderators should be able to unban threads if need be

The important thing is: although we have to play whack-a-mole with the spammers, we must take care to play whack-a-mole at as high a level as possible and not have to worry about the details.

Maybe.

I was thinking that if the server marginally decides a thread isn't spam, it should be easier for readers to overrule it, and so classifying threads into 3 threads is better than into 2.

I think your idea is better.