what would you do if you see a guy taking upskirt video of a girl?what will be your reaction?that happened today at the mrt station.this guy was like acting innocent standing on the escalator.me and my friend was at the back.we just stare at the guy

.he was like walking damn fast after he saw us staring at him.he
dashed into the toilet and locked himself inside for more than 5mins and we were like "sians,that guy sure hide inside dun dare come out alrdy" den we walk away.haha.what shud i do actually?what would u do?