I think the main issue is the aggregation between FB and WhatsApp data. FB promised/guaranteed not to do it in order to get the acquisition approved. They have

I think the main issue is the aggregation between FB and WhatsApp data. FB promised/guaranteed not to do it in order to get the acquisition approved. They have since changed their minds. FB would surely complain if the regulators also changed their minds and declared the acquisition illegal/invalid. > Facebook will no longer be allowed to force its users to agree to the practically unrestricted collection and assigning of non-Facebook data to their Facebook accounts