Topsy-Turvy and Patched

I logged in and saw these giant gray squares on my land. I thought they were prims, but I can’t select them, and they don’t show up as having any owners. It turns out, these things are randomly placed all over my sim and everyone elses. They show up as black spots on the mini-map. I’ve heard of patches for the Second Life viewer before, but land patches? I’m also seeing a lot of people who are turning there torso, arms and heads upside down into there legs. I’ve even seen myself do it a few times. Oh Linden Labs, what have you done to me today?