I have not been personally defrauded, but would like to report attempts:
Twice in the past two weeks (despite my being on the Federal Do Not Call list), I have received a phone call from a "John Williams" from the "Computer Support Help Desk" supposedly calling about my computer.
He did not ask for any person by name, and (as it happens) I do not personally have a computer. The first time he called, I told him this, so I could not get his number for it to be investigated. Today, I simply told him I couldn't talk right now and asked for his number to call him back at, and he gave me the 760-392-3952 number I listed above.
The only reason I can imagine someone making unsolicited calls claiming to be from a computer support help desk would be to engage in phishing or identity theft.