In a common letter, ten European cities, including Amsterdam, Barcelona, Brussels, and Paris, have stated that the massive growth of short-term rental platforms are increasing rents for locals and changing the face of neighbourhoods. According to the letter, the impact of these platforms must be on the agenda of the next European commissioners and must be regulated. The letter was triggered by the CJEU's advocate general opinion, issued in April, which stated that Airbnb, under EU law, should be considered a digital information provider and not a real estate agent. If the opinion is followed by the CJEU, Airbnb and similar online platforms will be able to operate across EU countries with no responsibility to ensure owners comply with local rental laws and administrative rules. The European cities believe that houses should be used as residentials primarily and for tourism secondarily. City authorities are also concerned that EU's efforts to foster e-commerce and sharing-economy platforms will prevent neighbourhoods from remaining affordable and livable for local residents.