""The Secret Service worked extensively with your committees, and agreed to search parameters provided by your office as to identify communications regarding Mr. Biden's travel," Secret Service Director James M. Murray wrote the senators on Feb. 14. "These search parameters did not yield communications for the years 2010, 2011, or 2013," Murray added." Apparently the search was limited to emails that satisfied certain "search parameters". Why didn't the senators simply insist on getting *all* the emails?