http://www.ign.com/articles/2014/12/25/ ... e-are-down
Now, Christmas is probably a very heavy traffic day for XBLA and PSN, as lots of people are getting new consoles and setting up accounts, and many of those folks and current owners are probably getting gift cards for downloads. So I imagine that the services are more prone to slowness or coming offline when traffic gets crazy.
But then in steps a hacker group to attack and bring down both services. No idea why, but I can't think of a single good reason to do such a thing. It seems it's basically to get some cheap laughs and no other reason.