Last year, Stack Exchange ran Winter Bash 2015, in which users earned hats which they proudly displayed upon their gravatar. There was a leaderboard of hatters, mad or not:
It's that time of the year again and we get to choose whether we want to do it this time around. Because of the popularity enjoyed by the previous years' bashes, all sites now opt-in by default unless the community decides to opt out.
What are hats, I hear you ask. Well, hats are kinda like ephemeral badges. You can choose to have one displayed over your avatar and you win them by certain actions on the webpage. Users can turn off hats on a per-user basis, so if you're against them for any reason, you can disable the feature and not see your hats nor those of the users who have opted in. As far as you are concerned, the hats will not exist.
Unless we choose to opt out, the event will run from 19 December 2016 up to and including 08 January 2017. After that, all the hats go away into Last Year's Hat Bin. More information will be available on the 2016 Winter Bash page.
If we want to opt out, we have to decide to do so by Tuesday, 13 December 2016. So, do we like hats or hate hats?