It could be a spittoon, which is designed for chewing tobacco. https://www.kegworks.com/blog/a-lesson-in-tavern-history-the...

But it seems like they also where used as urinals

I am a bit split this topic. There is some privacy concerns with using ipv6. https://www.rfc-editor.org/rfc/rfc7721.html#page-6

Some time ago I decided for our site to not roll out ipv6 due to these concerns. (a couple of million visitors per month) We have meta ads reps constantly encourage us to enable it which also do not sit right with me.

Although I belive fingerprinting is sofisticated enough to work without using ip's so the impact of using ipv6 might not be a meaningful difference.

its hilarious that you have privacy concerns while at the same time using meta ads.

I am guessing they're trying to limit the privacy harm to normal channels that the slightly savvy can understand rather than completely eliminate it.

Reportedly this is often incorrectly implemented, where /64 prefix is still a stable static address.