Intesting about Germany's sick leave rules which is different from USA. Generally, most private companies here in USA want to see note from doctor as proof so not to lose alot of $$ due to "sick" employees--some are and some lied. Also if employees take too many sick days, then the companies fall behind on work projects, paperwork, etc. Its another way of losing $$. Now, many companies are cutting down on the sick days to save $$ and reduce or cut off health insurance which is too bad, especially for the families with children.
I work for local gov't and my current boss doesn't ask for sick note if I miss one day. But last year, I was sick for 4 days and got doctor's note to cover my butt and to prove that I was really was sick and not playing hookey. My boss was cool with it. 
