That is in total violation of the Fourth Amendment. The Fourth Amendment forbids the above. In its plain wording it totally excludes such spying by government.
The Fourth Amendment to the Constitution of the United States
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized
See: Delatores - 5 articles, scroll back through using Older Posts link at bottom of articles.