Any riders who have recently bought a MetroCard at the Columbus Circle station near the No. 1 train platform may want to call their bank.

A rider Wednesday night spotted a credit card skimmer on the MetroCard vending machine on the north end of the train's southbound platform around 9:30 p.m., the MTA said Thursday. He ripped out the device and brought it to a station clerk, a police spokeswoman said. NYPD personnel then uncovered a camera hidden in a plug adapter mounted near the ceiling.

In response, the MTA launched a systemwide inspection of all MetroCard vending machines, which uncovered no other devices, according to spokesman Kevin Ortiz.

The agency will also start a public campaign telling riders to be on guard when buying MetroCards from machines, the agency said. Police on Long Island Monday spotted a suspected identity thief tampering with an LIRR ticket machine.

"We continue to ask our customers 'If You See Something, Say Something,' particularly if they notice any suspicious activity or device in our system," NYC Transit President Carmen Bianco said.