I suppose he means things like G20 violence in Hamburg a year ago. That included e.g. trying to kill and harm police officers.

https://www.dw.com/en/g20-violence-in-hamburg-german-leaders...

So (after reading the article), how is that in any way connected to the people impacted by the actions described here?

They sent donations to a free email service that the people calling for violent action against AfD happened to use. That's literally it.

A local branch of them was affected, too. Police did not care much whose rooms/buildings to raid.

The CCC have colaborated with extremists for some time.