are you saying that if you call that number, it is diverted to another number?
the answer is yes... each mobile number emits a signal which can be detected (location based). although this is not really done by the telcos, my sis-in-law who works in GT did this twice....first is when her daughter failed to come home, and some years back, when my wife is suspicious that i am having an affairs. hehehehehe.

but for general use, i don't think any telco will do this except for security reasons or with order by the court....

or if locator for that specific number is activated.