In September, hackers lit up the Green Building in a patriotic display of an American flag in honor of 9/11. The flag was the first use of the LED system that was later featured in the Tetris hack. Chris Pentacoff May. 9, 2016 Facebook Twitter Reddit Print In September, hackers lit up the Green Building in a patriotic display of an American flag in honor of 9/11. The flag was the first use of the LED system that was later featured in the Tetris hack. Chris Pentacoff