Stack Exchange celebrates the winter holidays by having a "hat" event known as "Winter Bash" which starts this year on December 19th and lasts about two weeks. Doing actions on the sites can earn you a hat you can use to decorate your avatar. Here's a list of the hats from last year as an example.
Some of the hats are easy to get, others are difficult, secret hats.
As a site, we can choose to opt out if there is a large number of users who do not want to earn hats.
So, do we want hats on Arts & Crafts?
As a note, if you do not want to participate as an individual, you can always opt out network-wide by clicking on an opt out button that will be available everywhere. It reads "I Hate Hats".