I work as an employee for an international corporation, and would like to try my programming skills developing applications for mobile phones and see if I can make some extra income from this. However, my current contract states that all my work, whether at the office or not, is property of the company. Others in the company have tried to obtain a "permit" to do such side business but were explicitly told they are not and will not be allowed to.
My question is, is this even enforceable at all? I'm currently employed in Germany so information specific for this country's laws is highly appreciated, though discussions of similar laws elsewhere are also interesting.
Many thanks!