Solid Oak, headquartered in California (hereinafter referred to as "Solid"), said on Thursday that Symantec mistakenly identified the CyberSitter filtering software developed by the company as a virus and forcibly disconnected the network connection of CyberSitter users in its regular security upgrade on Monday. A spokesperson for Solid said that Symantec's Norton AntiVirus software deleted or prohibited the operation of CyberSitter files. CyberSitter users are mainly from schools, libraries, and individuals.