A computer security firm said it had freed tens of thousands of slave PCs from a "botnet."

The slave PCs had to send out spam pharmaceutical ads and pick cotton for their plantation owners who, ignoring history, paid to watch them fight to the death. Tillmann Werner, a senior research scientist with a startup known as CrowdStrike attacked the Kelihos botnet live on stage.

He manipulated the messaging system used to control machines enslaved in the botnet and instructed machines to stop communicating with the servers that had enslaved them. He ordered them to start checking in with a new "command and control" server that he set up to protect the PCs.

Infected machines who checked into his command and control server were identified and showed up on a map on a video screen at the front of a conference room at the RSA security conference in San Francisco. A few hours later tens of thousands of infected machines had checked into the server of CrowdStrike and liberated. Now if only they could dynamite the plantation owner’s house.