New Tricks Fool Caller ID (washingtonpost.com)

"It wasn't long after caller ID became popular that some people signed up for telephone services to block their number from being displayed. Now comes another trick: Companies are marketing systems to help callers fool telephone identification services into thinking they are someone else entirely. "

New Tricks Fool Caller ID (washingtonpost.com):

VoIP hacks gut Caller I.D.

"Caller I.D. isn't what it used to be. Hackers have discovered that the handy feature that tells you who's calling before you answer the phone is easily manipulated through weaknesses in Voice over IP (VoIP) programs and networks. They can make their phone calls appear to be from any number they want, and even pierce the veil of Caller I.D. blocking to unmask an anonymous phoner's unlisted number."

VoIP hacks gut Caller I.D.