The Metropolitan Transportation Authority is urging subway riders who use MetroCard vending machines to be vigilant.
Police say a customer noticed a skimming device attached to a vending machine Wednesday night at the Columbus Circle subway stop.
The customer brought it to a station agent and upon further inspection, discovered a pinhole camera disguised as an electrical outlet over the vending machine.
The camera was hooked up to an external battery pack, which also had wires leading to the skimming device.
The discovery prompted the MTA to check all of the MetroCard vending machines throughout the system.