well, obviously it is ment to protect players from mosquitos...
iron curtain

It took some digging but I finally found this on another forum:
Fro: http://www.chessvibes.com/reports/anand-topalov-all-the-info/
Lots of confusion about the curtain – the audience will be able to see the players, but the players can not see the audience clearly. It will be lifted to let the photographers take clear pictures of the players, but then lowered in order to make visual signalling from the audience to the players impossible.
By controlling the amount of light in the auditorium, and ensuring there is more light on the players, the addition of this curtain makes it possible to fulfill Anand’s demand."
when i was watching some anand-topalov WC-match video's i saw a metal scan before the games... and one time i even saw an iron curtain pulled between the players and the public. it made me very curious!! now i found a video wich shows this curtain (after 1.30 min: http://videos.chessdom.com/anand-topalov-r3)and does anyone know what it"s for... anti-para psychology???
i searched for this clip again after watching the great movie "dangerous move"
complot theories are welcome.....
kind greets, jacco