Global spam drops by more than half %u2013 now what? %u2013 Naked Security. One of the worst botnets around has gone quiet since the end of last year. Nobody knows why; but, it really doesn't matter, because there are still enough computer criminals around to create havoc. Regular spam is still a problem; but, it just annoys you with ads for Viagra substitutes, and penile enhancement products. A botnet is a network of infected computers, owned by persons who don't know they are infected, which sends spam and phishing emails to millions of other computers. Sophos, the botnet referred to in this article, had 6,000,000 infected computers working. Ouch. But, you can reduce the likelihood that your network or computer is infected. Use your antivirus all the time. Get religious about keeping the virus and spyware definitions up to date. And, don't click on attachments to email unless you know where they came from. Simple rules; but, in the words of Shakespeare: "More honored in the breach, than in the observance". Be careful out there.