Last year was <A HREF="http://www.newsfactor.com/story.xhtml?story_id=41504">the biggest year yet for spyware,</A> as consumers, small businesses, and enterprises across the globe were invaded by a plague of malicious software. Trojan horses and system monitors were the most malicious types of spyware unleashed on computers, says software vendor Webroot in a new report called "The State of Spyware." Antivirus programs and free antispyware solutions are ineffective against these complicated and sophisticated programs, Webroot concluded.