Are community DMs private?

While using community.letsencrypt.org, are direct messages treated as completely private?
Or is the Internet able to crawl through them - completely public?

[yes I am a ‘binary extremist’ (sounds better than an ‘whole number absolutist’)]
[feel free to reply with an adequate amount of grayscale applied - or any amount of humor (sarcasm preferred)]

They are not private in that administrators can read them.

So not 100% private…
But can they be crawled?

They cannot be crawled, because they are not available without authentication.

Ok that is good (expected) news.

But to clarify some more…
Can any (random) authenticated user see messages they have NOT been included in?

Nope, they cannot. Only administrators.