The phone company and authorities can always track down phone numbers blocked with the star key and the number 67. Call blocking is a function of a caller ID system that is only available to the person answering the phone. There is another software that promises to be able to reveal prohibited numbers from the perspective of the end user.
When someone activates the call blocking feature, others are unable to see the phone number from which they are calling. However, because they are employing the call block feature, they are not immune to being discovered or convicted if they have been harassing or threatening others.
Most phone companies offer call trace in addition to call blocking. Users must dial star followed by the number 57 shortly after the call to activate this service. This may be subject to a modest price, and it may need to be enabled, depending on the company. The phone number is usually not shared with the customer and is only used for professional purposes. Another function is Call Trap, which reports blocked numbers to the appropriate authorities. Paid software like TrapCall claims to be able to show any blacklisted number to the end user.
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