Police stations are open around the clock. You can always submit a report online. In particularly serious cases, the Landeskriminalamt NRW can be reached under:
0211 / 9394040.

If you have become a victim:

Avoid danger

– Disconnect the affected device from the Internet, block Internet access (turn off your router or unplug the cable). 

– Turn off the affected device or unplug from the pocket, to save data. 

– Disconnect the affected device from the network to avoid endangering other structures.

Identify witnesses

Two different interests – two different paths

Offenders should be investigated 
Prosecution (German Criminal Code …)

Responsibility of: Police and State Prosecutor 

You can file a police report online. 
You can contact the criminal police or the office of the State Prosecutor. 
You can file a complaint at a police station near you around the clock. 

Compensation 
Civil rights (German Civil Code …)

Responsibility of: Lawyer, Consumer Protection, etc. 

You can engage a lawyer. 
You can get advice from Consumer Protection and they can put you in touch with a lawyer.