Most professional settings would not have permitted these company chat boards in the first place.

I have worked at a large company that actually did that we had internal newsgroups at BT bt.misc

And even externally the only thing that was verboten was the uk.telecom hierarchy - this was more to not encourage some of the internet kooks.

Are you really trying to argue that companies which for example use Slack (or a similar service) are "not professional"?

No, I'm arguing that most large, "professional" companies would not have allowed employees to create create chat groups whose sole purpose was to discuss politics or any other non-work-related topic (whether on mailing lists, Slack, or whatever). In doing so, Google was treating its employees more like adults, which is the opposite of what a previous comment in the thread was suggesting.

How did Google “treating employees like adults” work out? The only reason an employer goes to work is to make money. The only reason an employer hires someone is to make them money or to save them money.

Bringing anything else into the workplace is an unnecessary distraction from both the employee’s and employer’s standpoint. I go to work to have money deposited into my account twice a month and go home to spend time with my family and friends. The more time I spend at work spending energy not doing work either I will be less effective or spend more time away from family/friends/hobbies to be effective at work.

Yes. It's called HR and they will just fire you.

In my experience this is pretty common. My last company I used to get warnings for using swear words in private messages.

HN does this, we aren't even employees, and it's far far less serious of a site than a workplace message board. HN isn't even paying for my time like my employer is.

Seems completely reasonable for an employer to moderate internal message boards, of all entities.