Which law enforcement agency handles web scams?

I think I’ve stumbled on to a scam involving selling a car. If I’m right, who would I report it to?

The FTC, your state’s Attorney General (as well as the Attorney General of the scammer’s state, if different), and the State’s Attorney/District Attorney (i.e., the local prosecutor) of the scammer’s county would all be interested in this information. If it is local, the LAPD probably has a consumer fraud/web scams investigation unit as well.

The Secret Service also handles such cases. From here: http://www.straightdope.com/columns/read/2910/is-the-secret-service-responsible-for-keeping-the-president-from-getting-drunk:

In 1984 the Secret Service’s responsibilities were expanded to include the investigation of crimes involving banking, computer, and telecommunications fraud.

See also: http://www.ustreas.gov/usss/financial_crimes.shtml

The Internet Crime Complaint Center is a great place to start. This is a federal program, but they will work with local law enforcement (usually where the suspect is operating) to investigate. When I worked investigations, I had several scams referred to me by IC3.

It kinda depends on the scam. If it crosses state lines, the feds might get involved. If it’s something local, you might be lucky to get a city detective to take a look at it. It would probably also depend on the severity of the crime. Some local radio station having a glitch in their half-price gift certificate promotion would probably merit a warning. That same radio station selling your credit card information to some low-life in another state would probably merit a federal investigation.