Oh no. The trouble with “chat app with weapons sales feature” is that it is illegal to buy or sell weapons (online or offline) without specific licenses. Now I

Oh no. The trouble with “chat app with weapons sales feature” is that it is illegal to buy or sell weapons (online or offline) without specific licenses. Now If I made a “communication tool” exclusively for registered gun dealers and people with valid (and verified) hunting licenses, it would in fact be perfectly legal. Similarly, if the tool were for use by government agencies and defense contractors or registered weapons manufacturers, it would also be legit. In the context of “chat tool with personalized ads on the side” - there is nothing specifically illegal about “personalized ads”. Is there? (As long as there is user consent of course). So what’s the specific legal hurdle? Which paragraph of the GDPR prevents this?