How would this stand up to the "I didn't do it, I probably got hacked!" defense? It's one thing to publish personal conversation, and another to have your conversations aggregated by some LLM (and if they leak plain-text, the "hacked" defense is even more plausible).

So here's the deal with German law on this topic - there's actually a big difference between sharing someone's DM and running LLM tools on social media conversations. The OLG Hamburg case from 2013 (case number 7 W 5/13) establishes that publishing private messages without permission violates your personality rights ("allgemeines Persönlichkeitsrecht"). While we don't have specific LLM court rulings yet, German data protection authorities have been addressing AI technologies under GDPR principles. The Bavarian Data Protection Authority (BayLDA) and the Hamburg Commissioner for Data Protection have both issued opinions that automated AI processing of personal communications requires explicit legal basis under Article 6 GDPR, unlike simple sharing which falls under personality rights law. The German Federal Commissioner for Data Protection (BfDI) has indicated that LLM processing would likely be evaluated based on purpose limitation, data minimization, and transparency requirements. In practice, this means LLM tools could legally process conversations if they implement proper anonymization techniques, provide clear user notices, and follow purpose limitations - conditions not required for the simpler act of sharing a message. The German courts distinguish between publishing content (governed by personality rights) and processing data (governed by data protection law), creating different standards for each activity. While the BGH (Federal Court) hasn't ruled specifically on LLMs, their decisions on automated data processing indicate they would likely allow such processing with appropriate safeguards, whereas unauthorized DM sharing remains almost always prohibited under personality rights jurisprudence regardless of technical implementation.

That case describes publishing this to the public internet. I don't believe the same would apply when using a tool like this.

My family members all back up our conversations to Google Drive, I doubt WhatsApp would provide that feature if it were illegal.