live 8, how do the giant screens work?

Amazing show at london with the back screens, but are they just giant arrays of lightbulbs?

I had a good look on google -I still dont know he answer for sure but it looks a good guess that they were arrays of LEDs such as found here http://www.superscreen.com/led/en/20mm_panel.php?navid=15

There’s a big colour TV screen in London Waterloo station - it appears to be made up of RGB arrays of superbright LEDs - perhaps actually RGBW. The LEDS appear to be arranged in tiles, persumable each of these is an addressable module with its own driver circuitry.

Is this the same kind of screen used at the last Superbowl?