The present invention is a security tool for protection of data on a mobile computing device. The security tool provides a plurality of security policies to be enforced based on source information for the data and a location associated with a network environment in which a mobile device is operating. The security tool may be either located at the mobile computing device or at the server. The security tool includes a file access module for determining whether files are visible or accessible. The file access module comprises a tag generator, an association module, and a policy enforcement module. The tag generator creates source information for the file being accessed and the policy enforcement module determines what actions, if any, can be performed on the file and under what conditions such as location and network environment, type of file and other factors.