And that is why adding such a thing to standard vBulletin will never work. If all boards use it, spammers will only quicker find a solution to it.

How do you make it so your users can't have a link in their posts or signature unless they have 10 posts?

Pay mercenaries to hunt down the spammers and kill them.

j/k.

Have a good strong moderation staff, and if the person is a repeat offender, you can try sending their ISP an abuse email.

What bothers me about having to use hacks like that is this, while it's simple enough in theory for a new member joining to answer those questions posed. The problem is, it just adds even more to an already lengthy registration process. And can put possible new members off wanting to join, simply because they just can't be bothered with it all.

Make two usergroups.
One that has all rights you maximum want to give your members.
One that has some things turned off (like the BB code for images etc). Then use the promotions functions to have users promoted from the limited usergroup to the other after X posts. So set evaluation to posts instead of reputation.

That what I was just going to say. You'd have to make a new usergroup which standard members are moved too after so many posts. And disable the use of signatures in the standard members usergroup. But allow them in the new usergroup they get moved.

Just like the guy above said

add 163.com to that spammers list, they spam like crazy.

also add onestopsubmitshop.com and osss.com to that list. He'll come and spam your forums and PM your members like crazy

I am blocking every NON-us TLD as well as info and biz and a bunch of .com's maybe it will work for you, maybe it wont. It's kind of nice to not need visitors from other countries :)
Here is my list