All your base are belong to us (or AYB or AYBABTU or just All Your Base) is an internet phenomenon that came about when in 1992 the Japanese game Zero Wing was poorly translated into English.
A character named CATS made (now famously) the proclamation: All your base are belong to us.
From then on, groups of game enthusiasts began to digitally alter various images to include the phrase-the fire spread and a phenomenon was born.
The phrase is now commonly used as a battle cry for games, especially those played over the internet.
All the hype about AYB can be found here.