When starting two robot objects (and thus ROS nodes) you will get an error since the current implementation is not anonymous. We need to either:
a) Leave it the way it is, but inform the user with understandable error messages (in both python and web-interface). And describe this behaviour in the documentation. (We could also let the web-interface user inform about multiple logged in users).
b) Make the node anonymous, but inform the user of this behaviour.