You've probably been deluged by Spam in the last month or so selling penis enlargement pills or trying to get you to buy penny stock. A fascinating eWeek article gives details about the sophisticated bot net that's behind the Spam. The bot net is capable of sending over 1 billion email messages a day. That's quite a resource. Like anyone with a valuable asset, the bot herders have put considerable time and effort into growing, managing, and protecting it. The accompanying slide show is worth looking at as well.