An analysis of nukeSPAM™ data after a significant increase in blocked registrations on another site yielded some interesting results:

• Free and throwaway email accounts continue to top the list of spammers (and the site's blocked domain list has been significantly increased)
• Spammers continue to spoof IP addresses (no surprise)
• Gmail spammers insert random periods in the user name to enable one account to be used even after the primary email address is blocked

The screenshot of actual nukeSPAM™ data below shows the last 2 points (non-Gmail accounts - the first point - was filtered to highlight these points).  Read more for some ideas on how to prevent this with modifications to nukeSPAM™ and to RNYA.