threatpost: Spam Botnets Are Declining, But Likely Not For Long

“The size and volume of spam botnets are down over the last year, and much of this can be attributed to the effectiveness of IP-based blacklists. However, this defense method is no panacea as scammers have found new methods like reputation hijacking to circumvent these roadblocks, and bots continue to extend their reach by piggybacking on existing worms and viruses.”