Military-inspired technologies are coming home for use by local law enforcement.

Since 2001, federal grants from the Department of Homeland Security have been trickling to local authorities for counterterrorism efforts. But even years after 9/11, these agencies are shopping around for military-inspired surveillance tools that can keep watch on average citizens.

The rise of a surveillance state has raised questions about the legality of how law enforcement agencies acquire new technologies and inform the public of their use. Individual searches and seizures are protected under the Fourth Amendment, but laws addressing mass surveillance of the public are few and limited.