It's a lawyer's fee, not a fine
This is a lawyer's fee for the service of sending a cease-and-desist letter. It was capped to 100€ for simple cases by a recent law, and the court explicitly stated that it would apply in this case, except that the case was too old.
Previously it was quite a bit worse, lawyers abused the law to demand 3 to four figure sums and earn easy money sending mass cease-and-desist letters.
So the situation actually got better, you only risk a measly 100€ for leaving your Wifi open.
Biting the hand that feeds IT
