They basically just doxxed them, put up photos, names, account info of famous people, politicians and their families (at one point publishing photos and personal data of the little children of the host of a German late night show), and for a handful of them also published their entire iCloud content as well as all messages they ever sent/received on social media.
There's nothing fishy in there, just a very unethical and bad hack. Especially considering the hack only targeted left-wing people[1] a political motivation isn't be out of the question.
Footnotes:
[1] The hack targeted all parties that were at the time in parliament, but also many private people such as musicians, artists, TV hosts, etc. All of these people were politically left-leaning.