Twitter apparently turned down this request, claiming Yiannopoulos was a U.S. resident and therefore outside the scope of EU data laws. Today, Yiannopoulos filed an appeal of this decision, stating that he is quite clearly a resident of the U.K.  No offense but reading the article answers your question. They decided to "technicality" their way around it, probably until their legal and PR teams try to find a way out of this that doesn't play right into Milos hands.