If he was specifically going after famous women's accounts, I don't think it was so random, given that he went after hundreds of people and didn't cover his tracks at all. He was after celebrity photos, he was sloppy, people who try to defend against such attacks were going to catch him.
We've seen more decentralized and sophisticated attacks of the same type against iCloud ("the fappening" etc.) which were kept mostly private for years before being made public.
The fact that those hacks quickly were flushed from the news cycle without a bunch of public lawsuits etc. makes me suspect Apple very proactively went out and made settlements with the more high profile victims of those hacks. Of course, I have no proof of this at all, so it's purely speculation, but it was odd to see almost nothing come out of those hacks.
