Beside the new age data collection services such as YouTube, Facebook, Cloud Storage and so on. We have all heard people conversing in private about some subject and then go online to have advertisements served to them from the information in their private conversation. We have also noticed Apple's increasing effort to associate devices to the single person more so than in the past. However the central point of data collection is at the tower.
The wireless cell phone must communicate with the tower. The tower is the point to where your telephone calls are stored. Blackberry was the first company to create encrypted end to end calling and it was destroyed by the government because voice calls were unable to be eavesdropped. Their is no end to end encrypted phone calls they are illegal by government brute force.
Government control over the public is not about law enforcement and never is. n.b this is not about law enforcement. Instead it is purely about status quo and none more.
The government of the west have vast and expensive architecture incorporating satellites, ground installations and towers to collect voice data. This data has been used to suppress people deemed persona non grata and to listen in on defence contract negotiations. One defense contractor altered their bid after listening to contractee conversations preferring another bidder to win the contract.
5G & Huawei equipment is made by a non five eyes member and so governments are banning the equipment because it targets the towers. A central point that the five eyes use to collect voice and information data and that is all it about. Now many governments have laws against dragnet collection of data and without warrant but these are fake laws and have never been honoured by governments.