There are several tools and technologies used by governments for surveillance and tracking of people. Here are few famous examples:

Pegasus: Pegasus is a spyware developed by an Israeli cybersecurity company, NSO Group. It can be installed on a target’s mobile device, allowing the operator to monitor their communications, track their location, and access their personal data.

Facial recognition technology: Governments use facial recognition technology to identify and track individuals through cameras installed in public places. This technology uses algorithms to compare facial features captured in real-time against a database of known faces.

GPS tracking: Governments may use GPS tracking devices to monitor the movements of individuals. These devices can be attached to vehicles or mobile devices and can track the location of a target in real-time.

Stingray: Stingray is a device used by law enforcement agencies to intercept and track mobile phone signals. It can mimic a cell phone tower, allowing it to capture data from nearby mobile phones.

Internet surveillance: Governments may monitor internet traffic to track the online activities of individuals. This can include monitoring emails, social media activity, and other online communications.

There are various software products and technologies used by governments to surveil people online.  A few of these are below

XKeyscore: XKeyscore is a data collection tool used by the United States National Security Agency (NSA) to collect and analyze internet traffic. It allows the NSA to track the online activities of individuals, including their search history, emails, and online chats.

FinFisher: FinFisher is a spyware developed by a British company, Gamma Group. It can be used to monitor the activities of individuals online, including their emails, chats, and social media activity.

Carnivore: Carnivore is a surveillance tool developed by the Federal Bureau of Investigation (FBI) in the United States. It can be used to intercept and monitor internet traffic, including emails, chats, and other online communications.

PRISM: PRISM is a program developed by the United States government to collect and analyze internet communications. It allows the government to access data from internet companies such as Google, Facebook, and Microsoft.

DCSNet: DCSNet is a system developed by the FBI to intercept and monitor internet traffic. It allows the FBI to access email messages, chats, and other online communications in real-time.