In order to use Instant Messaging properly certain user data have to be available for potential chat partners. As side-effect, this data availability is an important part of the so-called awareness. This means that being an OLAT user you always know, e.g., who is online and how long as well as what that person is working on at the moment. This information can be found in the online user list to be activated on the below left next to your user name.