The House has passed the Truth in Caller ID Act of 2010 (PDF).
The bill makes it illegal "to cause any caller ID service to transmit misleading or inaccurate caller ID information, with the intent to defraud and deceive." In other words, spoofing apps that use caller ID are now illegal, or will be soon.
The bill maintains an exemption for blocking one's own outgoing caller ID information, and law enforcement isn't affected.
The change affects "any real time voice communications service, regardless of the technology or network utilized," i.e., this includes VoIP. In fact, the Congressional Research Service summary of the initial text makes clear that VoIP was a key target here.
The Senate already passed a version of the bill back in February, so this should be signed into law soon.
CTIA – The Wireless Association said that it supports "making caller identification spoofing illegal as the applications of such an activity are usually for malicious purposes."
What this means for us, the consumers, is that some of the apps currently available through the app store, and jailbreak, that do just this, are going away. This will obviously affect the iPad as well as the iPhone.
SOURCE: Ars Technica