Early last week, officials in Pirkanmaa and Central Finland found card copying devices installed on ATMs at four service stations. Later in the week, a fifth device was discovered at a service station in Vaajakoski in Jyväskylä.
Helsinki police say they have detained a man suspected of engineering the installation of the five illegal devices. Investigators say they have begun questioning him in relation to suspected payment fraud.
The skimmer devices were all passive, meaning that they recorded and saved card data but did not transmit them forward. Police said early detection of the devices and their confiscation prevented card users' information from being sent to third parties.
The Central Finland police department is investigating the case.
ATMs — especially at self-service stations — are checked daily for skimming devices. Police have created a video that shows members of the public how to detect card skimmers.
Police officials have uploaded a YouTube video (in Finnish) explaining how cardholders can recognise that a skimming device has been installed.
Card skimmers generally work by recording card data with a miniscule camera that captures the numbers in the cardholder's PIN code.