I dont have any idea but I know that using would insted of would is some how wrong (in this case)
"Would" implies the physical or mental capacity to do "it". "Could", on the other hand, appears to indicate one does not have the capacity to do "it".
The semantics would be different for each, so neither is correct, the context must be given. It is not fully explained as to what is being voted on: the popularity of the phrase? the correctness of the phrase?
JJ is just plain wrong when he says both are incorrect.
Geez, guys, seems that you have forgotten GRAMMAR! :D
this one is too easy for get a wrong answer!! obviosly! is could <----