...was that I should never write any email or document, internal or external to my company, that I would be unhappy seeing on the front page of the New York Times. Obviously this advice was from back in the days when a lot of people still read the NYT. Nowadays I guess the advice should be
"never write anything that you'd be unhappy to see 'trending' on Twitter or prominent on Reddit"
It seems that a bunch of people at Google, including many senior managers who should have known better, did not take that advice. Reading James Damore's lawsuit against Google (starting around the end of page 12, through page 44) he captured a bunch of invective-laden emails, forum posts and other internal content and his lawyer is using that as evidence that Google systematically discriminates against conservative viewpoints of its employees.
Now, I have no idea what the actual legal merits of the complaint are under California law - or any law system to be honest - but the individuals' emails and posts have handed Damore a giant stick with which to beat Google, and no doubt multiplied whatever amount that the lawsuit will eventually settle at. If they'd actually paused to think "how would it look if this email ever leaked?" then maybe this situation wouldn't be such a trash fire.
The alternative, mind you, is that the individuals did consider this risk, but thought "that's OK, all right-thinking people will agree with me when they read this." By their definition they may be correct, but I suspect that they will soon discover how much they are outnumbered by wrong-thinkers.
I'm going to be fascinated to see the reaction of the more conservative members of the press and blogosphere when they read through these posts.
Update: also look in the complaint at Exhibit B (page 74 onwards) with additional posts and memes. Holy crap.