Spam Jumps - BotNets the Cause?

I had noticed a huge jump in emailspam arriving on my Blackberry recently and Security Focus reports that BotNets may be behind significant rise in the global volume of spam in the past two months.

Estimates of the magnitude of the increase in junk email vary, but experts agree that an uncommon surge in spam is occurring. On the low side, Symantec has found that average spam volume has increased almost 30 percent for its 35,000 clients in the last two months. There has been a reported 450 percent increase in spam in two months, and the amount of spam filtered out every week by security software maker Sunbelt Software has more than tripled compared to six months ago.