Have only been there twice and both times we were handed stickers - not by the Delta agent, but the pre check in security screener - passport checker. Is it to make their job easier when looking for lost passengers - these things aren't small. I questioned it this time and I was told I "Must" wear it - yeah, until I was through security - they collect them again at the gate - hanging off pieces of paper that are taped to the counter. It seems to serve no purpose, other than to tick me off. Not the way to make their passengers enjoy their flight by treating them like school children.