Stick with me for some time, this may get pretty difficult and dizzy to understand. This isn't a bug that I want to resolve. It's rather a bug that I want understand and be able to answer "How it's possible?"
There is SMPlayer (Media Player) on internet. I watched "Seuss' Lorax" couple of times. I wanted just listen to a particular song that was sung in this movie. I started the movie, put on that certain moment when music starts. And I switched to Firefox (maximized), to work on website project. I looked on an place-holder image and it looked like it had some strange bug. It looked like few lines and pixels weren't working well. After few clicks and mini-research I found out, that the pixels are corresponding to image of movie. For example, when movie has majority of blue color, the image has also blue pixels. When over 10 minutes is mostly red, the pixels were also changing to red. When I tried to screen cap it and I move Paint to left, it disappeared. I also noticed this when I play flash games.
How is this possible?
@edit - It isn't only my website. It's on everything, when I maximize (not literally, just stretch it wide and high) SMPlayer and start anything, these points starts appearing mostly in regions where black is dominating.