Ugh, is there a reason your web page doesn't work with my PAGEUP, PAGEDOWN or arrow keys?
There's a circle numbered "9" in that same bad place, for browser developers who refuse to allow end-users to easily stop keystroke-hijacking and scrolljacking with a simple preference checkbox.
Explaining what I'd like to do to either group would probably land me in circle #5, and carrying it out would land me in #7.