I know in the world of popular music 4 guys playing music in a band are the most popular rock bands in the world. Coldplay, U2, Red Hot Chilli Peppers, Queen, The Beatles, The Rolling Stones, etc.
I'm a fan of Coldplay, but what annoys me is that when I see a performance or go to a concert of Coldplay, I feel a bit cheated when I can clearly hear keyboard sounds but I see no one playing any keyboard. I know that there should be an off-stage keyboard player playing all the sounds, but I would not feel cheated when they just put this person on-stage at live shows. It will also get rid of the rumors them not playing live.
And I know, they will no be displayed as a 4-members band, but it doesn't make their music less. You can just enjoy the econcert more.
Go to http://goo.gl/VQW4s and sign the petition if you agree with me. Hopefully they will read about it and take action.
On a personal note, I'm from the Netherlands. So If they just want to do it ones, 6th of September would be a nice day to do it :D.