Recently someone hacked Ubuweb and shut it down for a few days. It's back up and functioning in a limitted capacity now. If you'd like to read a bunch of academics and experimental filmmakers argue about the morality of this action (which has been assumed to be connected to Ubuweb's policy of not asking permission to post work and for a brief time listing artists who asked for their work removed on a "Wall of Shame" page) you can find such an archive of somewhat ridiculous (but sometimes very interesting) articles in the Frameworks archive here.
You can also just subscribe to Frameworks, you'll probably be sent an e-mail about this topic every five minutes.
Really though no one is reporting any news as to why this is happening. Philadelphia's own cinematic jewel Secret Cinema occasionally gets hacked as well.
Obviously there are cinephile cyber terrorists out there. If they're googling themselves right now, I would like to make it known that Shooting Wall would love to talk to you.
Ubuweb Twitter here.