When did we become so unaware and unconcerned with our ass cracks?

I saw something so disturbing this weekend I actually walked out of a retail store.
The employee behind the counter had on a pair of jeans which were designated "hipsters", and yes, she had a bit more junk in the trunk than is probably appreciated by the designer of those particular jeans, but no matter. To each his own right? What stood out to me was her trashy thong underwear which I could clearly see sticking out above the jean line.
So, if you can visualize... imagine with me... a sausage being choked by a farmer (in denim) and a dirty bow projecting from the death grip.
I stared and I stared like a stereo-typical American tourist in any other country. Almost hoping she would feel my stare and turn around to see where the heat on her ass was coming from. Hoping she would pull up her belt-less pants so I would not be forced to gawk at her crack with the dirty bow protruding from it. Desperately hoping she would just tug at the pants to cover the plumber crack with the feminine accessory accenting the inevitable downfall of American youth.
I have seen a lot of horrible Cosmo "Dont's" in the last decade, but this warranted attention. I felt like I was obligated to tell someone. But, I didn't want to get her fired, or embarrass her or even have her reprimanded at work, I simply wanted to shop without having to look at her ass. Is that too much to ass-k?