Is spoofing illegal?

Under the Truth in Caller ID Act, FCC rules prohibit any person or entity from transmitting misleading or inaccurate caller ID information with the intent to defraud, cause harm, or wrongly obtain anything of value.  If no harm is intended or caused, spoofing is not illegal. Anyone who is illegally spoofing can face penalties of up to $10,000 for each violation. In some cases, spoofing can be permitted by courts for people who have legitimate reasons to hide their information, such as law enforcement agencies working on cases, victims of domestic abuse or doctors who wish to discuss private medical matters.