Working nightshifts in a Barcelona hostel is a parallel universe of drugs, booze and horny British teenagers with second-degree sunburns.
Like Uber, but for breaking people's fingers!
Billy Corben's latest film, Dawg Fight, shows the people behind the punches in Dada 5000's illegal backyard fighting league.
You can achieve a lot more when you're not beating people up in the street.
Is it ever okay for teachers to lay hands on students?
We trained with Palestinian refugee and Brazilian jiu-jitsu master Samy Al-Jamy.