While a resident of Westridge Drive in Portola Valley was out of the country on a two-week vacation, someone ran up $40,000 in charges on his credit card, the San Mateo County Sheriff's Office reports.
He discovered the charges upon returning home Oct. 5.
The resident's home phone had several messages from his credit card company about the spate of purchases, the Sheriff's Office said.
The money was used for merchandise and services.
Authorities said they have no suspects.