The Millburn Effect is the sense of dread/anger/disbelief triggered by watching someone blithely make illogical and dangerous decisions that will have life-threatening consequences for themselves and others.
It is named after the biologist played by Rafe Spall in the Alien prequel science fiction film "Prometheus", who upon encountering a lethal-looking alien cobra, decides to pet it like a kitten.
It describes feelings of bewildered anger and anxiety resulting from watching people act with reckless stupidity and thus endangering themselves and others like the f**kheads they are.
"Why did Millburn try to pick up the space cobra?"
"Because he's a f*****g moron, lad."
"She's going to investigate the strange noise while alone in the house in her underwear. It's the Millburn Effect again."