So easy that there’s an article in USA Today this week about it that Slashdot picked up. As Internet-based telephony systems proliferate, so does the almost ridiculous ease they can proivide for spoofing the calling party’s number. In many VoIP systems the user can enter whatever number they want in a calling party field and that’s what gets sent out. The article also notes that web sites like Spoofcard.com and SpoofTel.com are popping up that provide easy and cheap spoofing services for those who aren’t using systems that they can confgure themselves. The main use of Caller ID spoofing so far has been by telemarketers, but you don’t have to think too hard to come up with plenty of nefarious possibilities.