Non-standard Scroll Control

It might be hard to see in the thumbnail below (click on the image for a full-sized version), but the purple tabs at top and bottom are the controls for scrolling the list up and down.

I see a number of usability risks with this design. First, it's a non-standard control for an action that is ubiquitous on the web -- scrolling. I didn't expect something that looked like a tab to control scrolling. Second, given the colorful and visually diverse content of the page, the purple tabs largely blend into the other elements on the page. Finally, the scrolling mechanism lacks a key element of feedback  that is present in standard scrollbars -- my relative location within the scrollable list.

From: Go2Web2.0