Mailing lists are awesome! E-mail is an open protocol so it's easy to write advanced filters that you can't do with Facebook or other walled gardens.

I had an algorithm trained to recognize free food, for example.

At MIT they can also double-up as AFS groups so it's easy to control access and message a team without having to update membership in two places.

Wasn't there a list for free food? (I assume you mean for mails sent to other lists..)

Op didn't say it was a complex algorithm. :)

It was a Bayesian spam filter I wrote and trained to recognize free food instead of spam. I signed myself onto about 800 mailing lists.

Probably generally old style hacker tradition. My company is also mostly email, email lists, and IRC.

more like what is it with the rest of the world that stopped using them (the answer is Facebook and IM, obviously)