Still illegal
Whilst I can, to a certain extent, agree with the comments regarding how sony deserve the treatment, this is still an illegal activity and should no be condoned.
Sony have lost my business due to their actions this year year, but I would never go smash their windows or anything like that. Also, even those these attacks have put a rather large amount of egg on the face of Sony, they have also caused widespread disruption for the poor souls who have spent money with them. Just because someone has spent some money on a PS3, or played some online games, they shouldn't be made to pay by exposing them to possible id theft. Not only is the attack on Sony illegal, but it could be classed as akin to theft from the users due to forced removal of a service.