Best thing we can do is report the spam posts as soon as we see them, it is very hard to keep spammers out since we are fighting an army of bots and people in other countries who pay people to crack the CAPTCHAs. 80% of the spammers I run up against are from Dhaka, India, Pakistan or the Philippines, if we could ban a whole section of IP addresses that would solve most of the problem but you might catch some innocent people in that net as well and that is where the difficulty is, how do you justify blocking a whole "city" from accessing the website when it is not the peoples fault but a small group of spammers..........