In the Verizon report, tampering refers to gaining physical access to an automated teller machine or a gas pump terminal to install a skimming device that reads data from credit card swipes. Card skimmers used by organized criminal groups is a top concern, according to Verizon. In 2013, 87 percent of skimming occurred on ATMs and 9 percent on gas pumps, Verizon said. Attacks against gas stations and convenience stores have become more sophisticated, with an increasing number of cases of data being exchanged over the network, an SMS text message or Bluetooth, without the criminal needing to return to retrieve the device. Verizon urges business owners to use newer tamper-resistant and monitoring terminals more closely for suspicious activity.