I wonder what the legal argument is behind this ruling. If one newspaper acquired another, couldn't the parent then market to the subsidiary's subscribers even if they continued to operate separately? The parent now owns everything anyway.
Data may be used only for the purpose it was collected and transfer to other legal entities require consent. In May 2018, the data orotection regulation ebters into force and the mandatory rules will be even tougher.
Maybe one day one or more of those companies will even have to pay a bit of tax in the EU.