I think you'd have to be grossly overfilled to cause problems, but it can cause problems. Having too much oil can cause excessive leakage into the cylinders that won't be burnt off during combustion causing none too great running conditions as well as oil spillage into the air intake system like Wiffmajig said.
When I change the oil I just measure the appropriate amount for a full change, what is it?... 5.4 Liters? I just know I need one and a third of those 4 L jugs of Mobil T. Of course I check the dipstick after running the engine a minute to verify but it's always been in the good range.