Just read a good article about dangers of wearing popular fashion item Uggs boots and especially their knockoffs
http://bit.ly/cYqU9d Apparently, because boots provide no support for your feet, they place stress on the muscles, tendons, ligaments, and bones. Everyday use can cause long-term problems for those who wear them, like flattening their feet.
I personally never understood the appeal of Uggs. They get dirty in the winter so quickly and look sloppy. I think they are the ugliest type of the boots, and if they are not all that good for your feet, I see no good reason to wear them at all. I am sure many people though, who wear them because they are considered fashionable, will dismiss doctor's concerns and continue wearing them.