[smsm42]

I love it how German seems to be able to put the whole law in one word :) It doesn't sound that stupid, depending on what "related" means - if it is indeed almost the same as you are being paid for, then it may make some sense (I'm not sure I agree with it, as it's basically means employer owns your thoughts, which seems a weird concept to me, but even if it is wrong it's not completely stupid). If it's just "it's all computer stuff so must be the same" then it's stupid. I'd say it all depends on how the courts will be treating it.

[Xylakant]

Overly broad applications are rare in germany. If you look at an engineering or research context it's easier to nail down: If you're a researcher the employer pays you for your thought and provides the lab, access to related research, to peers to discuss stuff with etc. Now you've been working on a particularly hard problem and the stroke of genius strikes you at midnight, you get up, work straight for two days and write down the formula you've been working on for years. It's worth a billion dollars. Technically it's during off-hours, so is it yours?