The report was welcomed by Privacy International, but the human rights group said it was left feeling "disturbingly hollow" with regard to Facebook's gesture. The group said in a statement: "Since documents leaked by Edward Snowden have been published and analysed, the veil has been lifted on what information governments actually collect about us.
"We are now aware of a terrifying reality - that governments don't necessarily need intermediaries like Facebook, Google and Microsoft to get out data. They can intercept it over undersea cables, through secret court orders, and through intelligence sharing."
Privacy International added that the usefulness of such reports "hinges on governments abiding by the rule of the law," adding that it is now known that these reports "only provide a limited picture of what is going on".