A major advantage of live phone readings versus in-person appointments is that there is no chance that the reader can cheat. During a face-to-face session, a reader can gather many clues and insights about a person based on demeanour, clothing, jewellery, hair, make-up, and overall attitude and appearance. The psychic might draw conclusions about someone based on those clues and form the reading around those things.
Wiegand card technology is a patented technology using embedded ferromagnetic wires strategically positioned to create a unique pattern that generates the identification number. Like magnetic stripe or barcode technology, this card must be swiped through a reader to be read. Unlike the other technologies, the identification media is embedded in the card and not susceptible to wear. This technology once gained popularity because it is difficult to duplicate, creating a high perception of security. This technology is being replaced by proximity cards, however, because of the limited source of supply, the relatively better tamper resistance of proximity readers, and the convenience of the touch-less functionality in proximity readers.
A common proximity format is 26-bit Wiegand. This format uses a facility code, sometimes also called a site code. The facility code is a unique number common to all of the cards in a particular set. The idea is that an organization will have their own facility code and a set of numbered cards incrementing from 1. Another organization has a different facility code and their card set also increments from 1. Thus different organizations can have card sets with the same card numbers but since the facility codes differ, the cards only work at one organization. This idea worked early in the technology, but as there is no governing body controlling card numbers, different manufacturers can supply cards with identical facility codes and identical card numbers to different organizations. Thus there may be duplicate cards that allow access to multiple facilities in one area. To counteract this problem some manufacturers have created formats beyond 26-bit Wiegand that they control and issue to organizations.
From its earliest beginnings to contemporary times, mediumship practices have had many instances of fraud and trickery. Séances take place in darkness so the poor lighting conditions can become an easy opportunity for fraud. Physical mediumship that has been investigated by scientists has been discovered to be the result of deception and trickery. Ectoplasm, a supposed paranormal substance, was revealed to have been made from cheesecloth, butter, muslin, and cloth. Mediums would also stick cut-out faces from magazines and newspapers onto cloth or on other props and use plastic dolls in their séances to pretend to their audiences spirits were contacting them. Lewis Spence in his book An Encyclopaedia of Occultism (1960) wrote:
Psychic Four was very motherly, constantly calling me "darling" and telling me how sorry she was for my loss. Her method of Emily-contact was a mix of prayer and coffee-dregs reading. She made me a small cup of Turkish coffee and when I finished the liquid, she placed the saucer on top of the cup, had me hold it with both hands while moving my arms in a circle three times and then flip the cup and saucer over and put it on the table. She put a blue glass cube with white circles on all six sides on top of the overturned cup and had me to put my finger on the cube and make a wish. I did, and she asked me for the photo. I handed her my phone. She put a small statue of a Turkish philosopher and an angel snow globe in front of me and told me to hold on to both and praying while she turned on her laptop and started playing weird reverb-heavy New Age music featuring a man and woman speaking about being intoxicated on love (not Beyonce style, unfortunately). She was going to ask Emily to make herself known to me.
In 1880 the American stage mentalist Washington Irving Bishop published a book revealing how mediums would use secret codes as the trick for their clairvoyant readings. The Seybert Commission was a group of faculty at the University of Pennsylvania who in 1884–1887 exposed fraudulent mediums such as Pierre L. O. A. Keeler and Henry Slade. The Fox sisters confessed to fraud in 1888. Margaret Fox revealed that she and her sister had produced the "spirit" rappings by cracking their toe joints.