An unspecified amount of the proprietary source code that drives Cisco Systems' networking hardware has appeared on the Internet, the technology giant acknowledged early Monday. A representative could not confirm, however, that network intruders made off with 800MB of code, as reported by a Russian security group over the weekend. "Cisco is aware that a potential compromise of its proprietary information occurred and was reported on a public Web site just prior to the weekend," said Jim Brady, a spokesman for the company. "The Cisco information security team is looking into this matter and investigating what happened." Read more: CNet News.