I kind of like them to be honest, almost like a badge of honor. I enjoy people seeing those and knowing that I fly international a lot. Chalk it up to as being a kid I never got to leave the state, and now I am jetting off to different countries and I'm proud of it/feel kind of important. Simple human nature I guess.

When flying back from Paris last year (CDG-ORD), I did online check in and had no checked bags so went straight to the gate. The person checking passports for the sticker at the gate seemed quite alarmed that I didn't have one, but then proceeded to ask me the standard questions (who packed your bag, has it been in your possession etc etc) and everything was fine. I wouldn't have thought it would be abnormal to not have talked to someone prior to that point, but apparently it was...

This happens to me all the time. Finally I remembered to do it at Frankfurt and asked for document check at the gate. They told me I didn't need it which seemed unlikely. When I went to board they noticed no sticker and booted me out of the line to wait for an agent.

There should be a better system. Perhaps online check in shouldn't be available where document check is required.

Just flew JNB-ATL. No sticker, no questioning. I found this odd.

Wow. I usually peel those stickers off after my flight because I don't like them on my passport.

Just flew BCN to JFK again yesterday. Agent in BCN notified me they had some security questions for me and proceeded to peel off the sticker. I literally chuckled at him, told him I figured this was coming and no worries I wear these like a badge of honor. He just laughed, dated the sticker, and told me to enjoy my flight. He didn't even ask me a single question after all. He must have taken my laughing it off and figured eh what the hell?

So two times ago I got questioned but no sticker, this time I got a sticker but no questions. Joy!

The questioning seems to have changed recently, my most recent trip was about where I live/work/whether I like the place I live.

ZRH issues "swissport" stickers (not ICTS) if flying UA, most other places seem to be ICTS. Also only on US airlines (of course...).

I got a Schiphol sticker flying DL out of AMS last year.

Yes had that at MAN quite a few times. The back page of my passport is absolutely totally covered in them