Oh, sorry, I didn't realize that CUFP was saying this. I searched for "chester bennin site:cufp.org" on Google and the only result returned was this page: http://cufp.org/users/genie
But you're kind of right. I can't really find information on Chester (from Linkin Park) doing functional programming.
It's either the guy on the picture really looks like Chester, or the said person (programmer) used Chester's pic as his avatar (unlikely, though, since they are a reputable sight).