There are various methods for acquiring the PIN; typically some type of observation is used:
- Personal observation: the criminal observes the use of the card reader and PIN pad from a distance with a telescope or binoculars, from an angle that allows looking over the shoulder' of the victim.
- Dedicated camera: the criminal installs a small camera, on or near machine of which the card reader is being skimmed, that is aimed at the PIN pad. Like the skimmer itself, the camera is optically blended in with its environment to avoid any suspicion. The camera recordings are either transmitted or stored in memory and later retrieved.
- Security camera: in case of an 'inside job', where the criminal has access to a video surveillance system by being employed at the skimming location, a surveillance camera is pointed at the PIN pad; the PIN entry can be then monitored or recorded through the surveillance system.
Another, more sophisticated method, is to place a pressure sensitive overlay on the keypad that is used by the skimming victim to enter the PIN. This overlay senses and records or transmits the keystrokes made when the PIN is entered.