ISPs have been known to do the same thing.

Devil's advocate, but maybe ISPs should all inject ads to make a point. They make money, and anyone using HTTP gets taught a free lesson on what MITM means

Before turning on the dude who thrives to keep the internet free, fix your corporate laptop that does MITM even for HTTPS connections.

"Free" for fraudsters to get their pickings, maybe.

I own a personal laptop?