An interesting thing I noticed while perusing my passport. Details:

In 2009, I was using a US passport and did not have a visa, but rather a German residency permit (Aufenthaltstitel). Because of this, I was generally treated like an EU citizen (including free admission to the Louvre!) and my passport was never stamped when travelling in the Schengen area. When I permanently moved back to the US, (German residency permit still valid, but expiring several months later), I never received any sort of exit stamp, nor did I get an entry stamp upon re-entering the US.

Do you think that Germany or the EU knows that I exited legally and didn't overstay my permit? Do they keep electronic records when/if they scanned my passport? I haven't gotten any other country stamps since then. And if it matters or makes things more interesting, I also exited via France.