LeCun was (is?) head if AI at Facebook.

He is a brilliant engineer, but I don't trust his judgement on things that affect human lives.

"engineer" is not wrong. But first and foremost, he is a researcher who invented deep learning, which is the foundation for modern neural networks. He no longer works for Facebook and is pursuing his own independent project: https://en.wikipedia.org/wiki/Yann_LeCun#AMI_Labs