Years ago Reddit had a sister site called Reddit secret Santa where Redditors could sign up to be matched with other Redditors as an online global secret Santa and you could write down your interests, likes/dislikes, hobbies, fav shows, movies, food etc.

It was pretty neat, I ended up with a lot of foreign nic-nacks and snacks because I would sign up for worldwide all the time

Secret Santa is where a group of people all get given the name of one other person, and they have to buy them a Christmas gift in secret. Someone else will buy them a gift, but no one (usually) knows who got them their gift.

Reddit Secret Santa was just the same, but on reddit, and instead of being among a small group of local friends (eg an office) it was done internationally.