It will never be a perfect solution (becuase people can be behind proxies and hide their IP) - but you generally match IP addresses with locations in the world people are.
Hi, A fast and simple solution is to block visitors from Bulgaria, or any other country in that matter is to use an .htaccess file to block traffic from this country. The site located at blockacountry.com can help you with this last procedure. Simply select which countries you want to block, in your case only Bulgaria, press the okay button and the website creates an .htaccess document for you. Upload this file to your server and your annoying spam visitors should be history. Wildcard
no, even they want to hide their IP, ARIN or whatever provider will still have their original IP address... so i guess you can research with those IP assigner lol..
you can and block with this script just go here http://www.phpscripts.9hz.com yuo have a lots a scripts but you download rar file named Banip.rar