I was flying SFO-DEN-MSN once and the DEN-MSN got canceled and I was re-accommodated the next day, but my bag was sent DEN-ORD-MSN. When I got to MSN my bag was there before I was, and when they got it form the hold it was covered with all kinds of stickers that it never had originally. They were all Chicago themed stickers, presumably for kids or tourists. I found it mildly entertaining and they all peeled off very easily. And yes, it was my bag, with all of its contents. I think someone in ORD was just having fun.