Here are several usages.
1. Anti-tracking~conceal your location
Anti-tracking is the common usage for GPS jammers. Some individuals use GPS jammers to block tracking devices, preventing others from monitoring their location.
2. Preventing detection by police in order to avoid fines or tickets
Some individuals use GPS blockers to prevent the police from detecting their vehicle's speed, location, or violations. For example, drivers might use devices that block speed radar signals or GPS tracking to avoid speed-related tickets or fines. This is usually illegal as it interferes with law enforcement activities.
3 . Blocking GPS/2G/3G/4G/5G/WiMAX/Wi-Fi/Bluetooth/Lojack connections
People may use GPS car jammers that can block Wi-Fi and Bluetooth/Lojack Signals, stopping mobile phones and other devices from being able to send or receive messages, calls, emails, and other notifications
4. Preventing devices from being located
Many devices, such as smartphones and vehicles, can be located using GPS or cellular signals. GPS car blockers can be used to make it difficult for anyone to track the device’s location.
5. Concealing one’s location from an employer while driving a company vehicle
Employees may use GPS jammers in company vehicles to prevent their employer from tracking their exact location. This often happens when an employee wishes to avoid being monitored during personal activities, especially if the company tracks vehicle routes or mileage.
6. Avoiding tolls and mileage charges
Some drivers use car GPS jammers or other techniques to avoid electronic toll collection systems, such as those that rely on GPS, RFID, or other tracking technology. By blocking the system signals, drivers can avoid paying tolls or having their mileage recorded.