The Twitter Inc will host US citizen accounts while a separate subsidiary called Twitter International Company which will be based in Ireland will handle all non-US Twitter accounts. Twitter has chosen Ireland because of Ireland’s lax privacy laws. The reason for doing so is ostensibly to escape the court request which come from NSA and other US authorities about user details.  Ireland has one of the most relaxed privacy laws in Europe and as per the current Irish laws any data processed in Europe is not made available to NSA without explicit consent of an Irish court. Moreover, the upcoming cyber security bill and privacy legislation in European Union which will make it more difficult for US-based companies to share data about European users with advertisers. Twitter Inc which is headquartered in San Francisco will look after all the US based accounts. Twitter’s Periscope will also be similarly affected. Twitter announced the future changes in the policy update post: Of course avoiding the NSA or making advertising easier are not quite how Twitter explains the reason for the change: If you live in the United States, the services will continue to be provided to you by Twitter, Inc., based in San Francisco, California, under United States law.” However how this will work out in real world is really a big question Twitter will have to answer itself.