A warrant is required, and an affidavit to be ‘proper and legal’. One each for Search, Seizure, and or arrest. ALL warrants are required to have an affidavit specifying what is being searched for, exact items to be seized, and cause for arrest. I suggest that each tech company only open an electronic message upon presentment of a ‘proper’ warrant. Forget the ‘blanket’, one size covers everything approach. Do this right, and I have no objections.