I just had an interesting experience in CDG earlier this month on a CLL-DFW-BNA-DFW-CDG-XDB-CDG-DFW-CLL butt-numb-a-thon run. When checking in with AA security for the flight back to CDG, the agent noticed that I had arrived at CDG that morning and was leaving already.. so asked all sorts of questions about what I did, where I had been, if I knew anyone in Lille (where I had been for all of 30 minutes), etc. Wanted to see boarding passes, business card (don't usually carry them), train tickets etc. Then he led me through immigration, security, where they did a pretty thorough bag search and body pat down. This was odd for CDG; in my experience usually I'm just waved through, at least half the time my passport isn't stamped on entry/exit either.