European lawmakers threatened on Tuesday to unpick data-sharing agreements with the United States, reacting furiously to reports that U.S. authorities have accessed emails and other personal data from leading Internet companies. The news has forced European governments to explain whether they let Washington spy on their citizens or benefited from snooping that would be illegal at home. In a heated debate in the European Parliament, lawmakers complained that for a decade they had yielded to U.S. demands for access to European financial and travel data and said it was now time to re-examine the deals and to limit data access....