A botnet is a network of computers under control of one user, unknown to the rightful owners of the computers. They can be used for denial of service attacks, identity theft, sending spam e-mails and spreading more "malware" to link more computers into the botnet.

FBI officials said a number of holidays last year were used to spread the Storm Worm through messages with links to supposed e-cards.

Computer users are warned to avoid any Valentine's Day mesages sent by unknown admirers, leaving suspicious e-mail unopened and especially not clicking on links in the e-mail.

To receive the latest information about cyber scams visit the FBI Web site and sign up for e-mail alerts by clicking on one of the red envelopes. If you have received a scam e-mail, please notify authorities by filing a complaint at www.ic3.gov . For more information on e-scams, check the FBI's New E-Scams and Warnings Web page.