It is him. He confirmed it on his myspace. The link is probably wrong because he can't type.
: I DON'T think it's JC. The twitter page links to http://www.myspace.com/johncusak, which is not John's myspace.
: It's way too out of character for John to even have a public Twitter, unless he had gone through a massive personality change. The person doesn't even sound remotely like John.