actually, you want to know where it comes from? a while back, there was a HUGE wait for the unreal tournament 2003 demo. On the official boards, a thread called 'I am about to join them' was started showing pictures of protestors holding signs saying 'we want the demo' or something. The thread refused to die and there were thousands upon thousands of these pictures. some incredibly funny. Anyway, someone posted a picture with the words 'give us teh demo' written on, purely by accident. Then suddenly everyone was using it for each of their own pics - 'teh' was suddenly being used everywhere.
Interestingly, when the demo finally came out, the surge to download it was so huge that the internet actually broke. No joke, the traffic built up on so many fileservers worldwide that the internet came to a complete standstill.
Then everyone played it for twenty minutes, went back on the official forums and bitched about it.
Can't win 'em all.