There was a recent court ruling by the European Court of Justice about net neutrality (source, unfortunately in German). Essentially the operators where offering plans with a limited full speed download but some specific services (for example facebook, spotify, etc) were excluded from the download count. So once a user had used up their monthly say 1 Gb of download at full speed, further downloads would be significantly reduced in speed with the exception of some listed services. These kinds of plans were ruled illegal because they breach net neutrality.
Question: What are the consequences of this for mobile phone operators?
They should stop offering these plans and change existing plans. But they presumably profited from these plans in the past, and while the court ruling is new, the law is not. So do they have to pay some kind of compensation to customers who had such a plan? Some kind of fine for offering something illegal? Or does the court ruling only have an effect from now on so the past is the past?