Data Fence is a personal security tool to monitor access to your data, alerting you when hackers, government spies, or overly curious co-workers access your personal files. It can also be fun just to discover all the activity that occurs behind the scenes such as when you create a document or plug in a USB thumb drive.

Data Fence leverages Apple's BSM audit data to put a virtual fence around your data and to alert you when your data is accessed in a suspicious way. It doesn’t care what the malicious software looks like. It doesn’t care if a bad guy has logged in with stolen credentials. It doesn’t care if you let a user mount your file system to access just some of your files. It doesn’t care about any of the ways the threat might manifest itself, but it does care when the threat accesses your protected data.