[cookiengineer]

Fun fact: deletion of your messages is not possible. Meetup can only manually delete all user data, and doesn't have a possibility to delete data by purpose.

I filed a complaint to the Datenschutzbehoerde here, but the legal process takes a while.

If you want to do something against this, find out who is the representative for your state or country, and tell them about it. Usually they have a website for this, and need some screenshots or documents as evidence to start the legal process.