phone spoofing

How is it legal for these telemarketers to call and use a spoofed, disconnected phone number?

How is it legal for these telemarketers to call and use a spoofed, disconnected phone number?
The other day my phone was ringing and it said some college on it. I wasn’t sure who might be calling, thought perhaps one of the multitude of random women that cannot control themselves and leave me alone, so I answered it and it was a BS spam mortgage call. Call the number back and it was disconnected. What the F is that? Capitalism / consumerism ?
I can put the numbers on here.. they are ‘masking’ their number to try to get people to pick up the phone, most likely, because some number cruncher figured out that it is better to get the person on the phone, regardless…

You can solve the problem by putting your numbers on the national Do Not Call Registry. As for the disconnected number, are you sure it was not just a number that does not accept incoming calls? I have has dealings with such numbers and they are not illegal, but they are a pain in the neck

Spoofing Resources
phone spoofing

SpoofCard – Caller ID Spoofing – 60 Minutes $2.50 SpoofCard offers the ability to change what someone sees on their caller ID display when they receive a phone call. Simply dial SpoofCard’s toll free number or local access number in your country and then enter your PIN. You’ll then be prompted to enter the destination number followed by the phone number to appear on caller ID. It’s that easy!…