A valid question, I wondered the same. In the US, at least in my state, search warrants have to be specific about what is being searched for, where to search f

A valid question, I wondered the same. In the US, at least in my state, search warrants have to be specific about what is being searched for, where to search for it, and when the search should occur. So I think the warrant would likely have mentioned what sorts of messages they were looking for between dates X and Y, not just that Meta was ordered to turn over the entire message history for a user.