The new Lion OS. In Snow Leopard the scrollbars were visible and substantial. They were irritatingly a couple of pixels narrower than a Windows scrollbar but they were good enough. But in Lion Apple haven’t asked someone with limited fine motor control to check how the scrollbars behave for them. Apart from having to make them visible in the first place that are really narrow now and there is no indicator that shows they have been grabbed by the mouse. This makes clicking on them much harder and that means more frustration. Apple didn’t even see fit to address that in the Accessibility prefs. Looks like Apple employ only the beautiful people with perfect control.