I can buy my own 800 number for $8, but more than than, I can type any number I want into the command prompt on an asterisk box and have it show as the CID on m

I can buy my own 800 number for $8, but more than than, I can type any number I want into the command prompt on an asterisk box and have it show as the CID on most phones right now. I could literally start running this scam myself in 20 minutes for less than $5. Caller ID is not a secure system at all. Anyone can type anything. Its like the "from" field in an email.