The reason is simply because these systems are also authoritarian centralized systems and have felt the danger of the spread of anti-central awareness and they know that people's love of privacy and attention to this aspect of the disease grows stronger
What is not known to everyone is that Facebook loaded and bullied on the encrypted currencies and the technology of the blockbuster in particular came coincided with the scandals of loud tremor Arush these sites, which have been manipulating and trading personal information for users for years, and that their hands have extended to all other data on the device such as pictures and SMS messages Contacts and even spy on calls and cams and hidden the greatest ..
Everyone should know that the step taken by Facebook, Twitter and Google to ban ads for encrypted currencies is only the first step to fight decentralization and not to protect users, as some would think if they were really protecting users because they did not commit all of these crimes in violation of user privacy.
They originally felt that there were new social networking platforms on the basis of blockchain , which started to take their place in the world. I really hope that these platforms will succeed and we will rid ourselves of the tyranny of these sites in the future.