At least on OS X there aren't scrollbars visible until you need them (start scrolling). There is that small hint on the top right, but if the page is scrolled

At least on OS X there aren't scrollbars visible until you need them (start scrolling). There is that small hint on the top right, but if the page is scrolled any amount--even an amount that doesn't move the page at all--the hint goes away and there are no visible scrollbars. It's a terrible UX.