Many of the other stackexchange sites enable a festive wintertime custom every year in late December, the Winter Bash, in which user profiles are accommodated with fanciful hats, earned for various accomplishments on the site, something like badges, except that they are temporary and often whimsical.
I enjoy the hats on mathematics.stackexchange, which are great fun and absurd. You can see various users in hats on the user page over there — here is the hat I am currently wearing:
This is all innocent fun, which doesn't interfere in any way with the functioning of the site, which lasts just a few weeks at the end of the year, and which furthermore helps build community.
Question. Shall we have Winter Bash hats on MathOverflow?
Vote up for yes, down for no, and post an answer with your arguments or comments.
The question was considered years ago here, but I don't see much of an argument given there for why we can't have hats. Let us have hats!
It would be completely optional. Just to be clear, let me also mention that participation with the hats is entirely optional — you certainly don't have to wear any hats yourself and there is a one-click option to make all hats disappear for you, if for whatever reason you don't want to see them.
It can be enabled opt-in only. The hat capability can be enabled as opt-in only, so that by default nobody sees any hats, and those wishing to partake in the absurd fun would specifically opt in to do so. Everyone else would carry on blissfully unaware. [Update. Evidently, the opt-in feature is not actually available at this time, as I had been led to believe in discussions on stackexchange.]