Is the use of air scanner illegall in Germany ?

[brianw999]

but sometimes I hear things like e.g. "we have 24 persons an board, we had no problems, we´re near Eindhoven airport" (in Dutch!). Don´t know what it is.

That's probably a company private channel. Conversations on these frequencies are often in native language as they are not part of ATC procedures. Company channels may be used for such things as reporting a maintenance need on arrival, requesting wheelchair assistance for a disabled passenger etc.