I use the Flashblock Firefox extension, mainly because I do not like having distracting animated stuff going on in the corner of my eye when I am trying to read the content on a web page. (I use the escape key to kill animated gifs.) It also eliminates a lot of those annoying objects that float over a page as you are trying to look at it. Flashblock does not make Flash objects disappear altogether however, it puts an icon on the screen that you can click to allow the Flash to play. This means, for instance, that you can still play Flash videos, as on YouTube, with just one extra click.
However, I have noticed that quite a lot of these “blocked Flash” icons, that I find on various pages, appear to do absolutely nothing when I click on them. When I click, the icon just disappears but nothing else appears to happen. No video or animation or ad appears. I do not think this a glitch; I am fairly sure that this Flash is not supposed to display anything. I see quite a few flash objects like this on my bank’s site, and I was inspired to ask because I just found one at the bottom of Cecil’s “Today’s Question.”
My question is, what is this “hidden” Flash doing? Is it some sort of tracking device, beyond regular cookies, or maybe it enables some aspect of formatting beyond HTML and CSS, or . . . what?