The concept of authenticating users e.g. by means of a login process is very well established and there is no doubt that it is absolutely necessary and helpful in a multiuser environment. Unfortunately specific information about a user originating a data stream or receiving it, is often no longer available at the traversed network nodes. This applies to the even more specific question of what application is used as well. Routers, gateways or firewalls usually have to base their classification of data on IP header inspection or have to try to extract information from the packets payload. We present an approach that works transparently and allows to associate user and application specific information with IP data streams by only slightly modifying components of the operating system environment and infrastructure components. On top of this framework we show usage scenarios for dedicatedly placing copyright information in media content and for an enhancement of the interoperation with the security infrastructure.