How can the National Intelligence and Security Agency and the Intelligence Service locate a person using only their phone number?

This is a common question, and the answer is quite simple:

1- They need a court order against this person to obtain their information.

2- What is the mechanism by which this information will be obtained?

Look, my friend, you know that every device has two things (IMEI and IMSI). These are present in the device and are very important. They contain information about the device and also information about the company that issued it.

When you buy a SIM card and put it in your phone, and then you top up your credit, make a call, or even just it picks up a signal, what happens? During any operation, your device will send information (IMEI and IMSI) to the company along with the device's exact location and its proximity to which cell tower—that is, which tower the signal is coming from. Therefore, they will know all your information, including the information registered on the SIM card, its location, and device information.

So, one question remains:

Why are some SIM cards or numbers difficult to track or trace their origin?

For example, "phantom lines" or what are called "phantom lines"

Firstly, these lines are registered under other people's names, meaning their information differs from yours. Secondly, when you buy this type of line, data will be continuously transmitted, but the person's identity will remain unknown.

Note: Even if the person changes the line, their digital fingerprint will still be present and they can be identified.