With Google’s recent monopoly status being a topic a discussion recently. This article from 2017 argues that we should nationalize these platforms in the age of platform capitalism. Ahead of its time, in fact the author predicted the downfall of Ello.
Maybe not a warrant, and IANAL, but government agencies aren’t necessarily at liberty to share information amongst themselves. For instance, IRS needs a court order to share returns with law enforcement (IRC Section 6103(i)(1)).
But yeah…this seems like maybe not a super great solution…