This is an old link, but contains all the information needed. They’ve watered it down a bit since, but you still see it pop up from time to time: https://www.theregister.com/2017/05/19/open_source_insider_google_amp_bad_bad_bad/

edit: oh, someone else posted the exact same article, haha. I didn’t look at the context, just replied directly from my inbox. Well, I’m leaving it here, so everyone can see me embarrassing myself :)