And spammers could create lots of accounts, wait until each is mature, and then unleash it. How can you tell the difference between a spammer that creates a ste

And spammers could create lots of accounts, wait until each is mature, and then unleash it. How can you tell the difference between a spammer that creates a stealth account and a lurker that still doesn't have anything to say, but is creating an account so he can eventually participate fully?