That is a waste of or an invalid warrant then, as the correct response to a warrant for something you don't have isn't everything you do have, but the null set.
That's still problematic though, because with clever orchestration of multiple warrants, you essentially figure out the "shape" of hidden information anyway, until you can get the request just right.
The idea though is that a judge should get tired of signing warrants for the same person by that point though, as it should not be an automatic process, and should only be being done on a case by case basis as evidence or procedure requires.
A warrant for all the data you have about a person activity in 2019 is perfectly covered by giving only December data if that is all you have. A warrant obviously needs to be a bit larger in scope than needed, at the very least by requiring data that is relevant to the data you are interested in.
