The US government has been using 'keyword warrants' to track individuals who search for specific terms on Google, which has sparked concerns over privacy and civil liberties. These warrants require Google to provide user data on anyone who searches for certain names, addresses, or phone numbers. The practice has been used in investigations, including a 2018 serial bombing case in Texas. Google has defended its decision to respond to these warrants, claiming it protects users while supporting law enforcement.