Thin plastic gloves in a grocery store? I've been in Paris for 14 years and have yet to see that. Maybe you shop in nicer places than I do.

I have to second the post above about Galleries Lafayette, although my experience was at Bon Marche, relatively recently (maybe 5 years ago). I knew better than to handle merchandise in a small shop, but this was not even a "boutique" inside the department stor, there I was looking at purses, arranged on a flat table display, picking them up and unzipping them to see how many pockets inside, etc. when I was told what I understood in French was not to do that, that the saleswoman would open and show me. By her tone of voice it was more a command than an offer. Now I always ask first!