Caller ID Spoofing is the method of making your caller id number appear as someone else. Typically this is done by spoofing ANI information that is sent out to the PSTN (Publically Switched Telephone Network).
Debt collection companies and private investigators have been using this technology for years but there is a service that makes it available to you, very cheap and all you need is a phone. Land line, cell phone or internet phone it doesn't matter.
This how to is going to show you step by step how to spoof your caller ID using a service called TeleTurd <-- strange name indeed.
Step 1: Sign-up for caller id spoofing (Free 5-Minute sample)