Companies came to Ireland for the tax benefits, but stayed for the regulation.
Facebook was the first to declare that users outside North America have a legal relationship with its Irish subsidiary (see section 19), not the American mothership. According to the company’s third-quarter report for 2013 (pdf), that is a total of 990 million people. LinkedIn did the same for its 175 million users, including Canadians, who live outside the United States. Adobe followed suit. Dropbox is expected to do so soon. (Google retains California as the sole jurisdiction for any issues, data-protection-related or otherwise.)