Oh, the nutter is definitely real. Pastor Terry Jones from Westboro Baptist Church. He specialises in "God hates fags", and has recently moved on to "God hates Muslims". IIRC, Louis Theroux did a TV show about him years ago.
Presumably the singing and the filming were set up by the (credited) producers to deliberately disrupt his obnoxious preaching.
Terry Jones' outfit is the "Dove World Outreach Center". The Westboro Baptist Church is a different organisation run by Fred Phelps.
Phelps planned to trip to the UK in 2009 in order to picket my old school, in Basingstoke of all places. Ultimtaely, he was refused entry
Delftse Post, the epitome of Cycle Chat Cool, is from Basingstoke! I'm going to have to forget everything I thought I knew about anything.

Winchester is worse than Basingstoke!
I prefer to think of it as being from "near Winchester".