It's called fashion!
There is a South Korean clothing brand that is selling something called "Slash" jeans, according to BoingBoing.com. From the waist to above the knee these pants look normal, then you get about halfway down and there's a slanted cut across both pant legs. So the top half of each leg doesn't quite line up with the bottom half. People think there's a glitch in the Matrix, or it looks like a ninja took a Samurai sword to them. It kind of looks like the top half of your body is sliding off of your lower legs, which is probably why they are called "Slash Jeans".
You can get these jeans for the low price of $375 or you can take your favorite pair of jeans into the garage or wherever you keep the garden tools and take shears to them and it would be cheaper. You can see what these pants look like below and if you want a pair, you can preorder them, HERE.