Not a fed but I would think yes in aggregate. Depends on what you're looking for. Plenty of needles in the haystack.
Discussion
Used to work a lot with the feds and agree that "it depends". An interesting aspect of this is that the legal threshold to obtain metadata is sometimes lower (requiring an administrative subpoena) while the standard for actual content is higher (requiring a warrant supported by probable cause). And sometimes the former can strongly support the latter.