I would not stoop to his level of name-calling and insults. That is what Barefoot is aiming for and where he gets his kicks from.
Just whack him with the facts; he cannot reply without making more claims that contradicts his old ones, and as such, he gets even more frustrated and acts even more childish. That's where I get mine from, and from where everyone should.
Don't let little Barefoot turn this into a playground.
It's enough for me to wind him up by posting ridiculous assertions like "slavery is legal in the USA".
Then watch him dance.