I'm becoming numb to it (not to having my crack exposed, to seeing it on others, I mean) because of being in college. You really can't go a day without seeing it. <sigh>
I wear hip-huggers, but not the super low ones, although I do kinda understand how it happens to these poor girls, because it can be hard to find ones low enough that they don't feel like Mom Jeans, yet high enough that they don't slip down when you sit.
Plus, I've noticed that once you get used to a lower rise, you tend to pick lower and lower ones. It's like a drug-- you keep needing a lower rise to feel like it's low enough...the rise you had last year seems way too high now...