I'm not a lawyer so maybe I'm misunderstanding something but the plaintiff is Whatsapp, not the journalists. This isn't really about holding NSO Group accountable for hacking journalists at all The fact journalists were compromised seems only incidental, the ruling is about weather or not NGO Group "exceeded authorization" on WhatsApp by sending the Pegasus installation vector through WhatsApp to the victims and not…
> I doubt I'm the only person here who has ever made an alternative client for something before
I think the distinction here for "exceeds authorisation" is pretty apparent. I don't read this judgement as being damning for people wanting to make their own clients.
They made a third party client for deliberately malicious purposes. If you go ahead and make a discord client with the intention of spamming or otherwise causing harm to its users, I think it's completely reasonable for you to get in trouble for that.