Tom was playing around with FireFox yesterday and came to the realization that the auto-scroll icon is actually inserted dynamically into the document’s HTML, but outside the HEAD and BODY — meaning it’s still within the clutches of our evil CSS.

Mwha Ha Ha HA!!

Try clicking your middle mouse button anywhere onscreen in FireFox 1+ to see the results.

Here’s the CSS:

html>img
{
width: 0!important;
height: 28px!important;
padding-left: 28px!important;
background: url(/images/icons/autoscroll2.png);
}

In reality this is a known bug, so can’t really be relied on into the future (though it’s been around for a long time), but if your client is looking for that little bit of extra branding…

Source Link: http://www.sitepoint.com/customizing-the-autoscrolling-icon/