Cisco Umbrella is a security tool which blocks access to inappropriate (porn, gambling, etc.) or insecure (viruses, malware, etc.) content on the Internet. It is installed as both an App and an Extension on Chromebooks. Cisco Umbrella enforcement is in effect regardless of where the Chromebook is located or how it is connecting to the Internet. Although Umbrella is a very helpful security tool, a determined user might possibly find a way to bypass it.