Most card readers are highly portable and versatile in their ability to read more than one type of memory card. The most common types of memory cards are Secure Digital (SD), microSD, SDHC, microSDHC, CompactFlash (CF), Memory Stick (MS), MS Duo, Mini SD, and MMC. Before buying a reader, make sure it's compatible with the memory card you are using.
The exposures of fraudulent activity led to a rapid decline in ectoplasm and materialization séances. Investigator Joe Nickell has written that modern self-proclaimed mediums like John Edward, Sylvia Browne, Rosemary Altea and James Van Praagh are avoiding the Victorian tradition of dark rooms, spirit handwriting and flying tambourines as these methods risk exposure. They instead use "mental mediumship" tactics like cold reading or gleaning information from sitters before hand (hot reading). Group readings also improve hits by making general statements with conviction, which will fit at least one person in the audience. Shows are carefully edited before airing to show only what appears to be hits and removing anything that does not reflect well on the medium.
Jean Pierre Allaire was counselling a 13-year old Trois Rivieres girl who reported seeing people that others could not. He told the girl she should go to the medium to find out whether she has a psychic gift. He also told her not to tell her psychiatrist about what she was seeing and hearing because that might lead to an increase in the anti-psychotic medications she was taking, which were making her sleepy.
Many 19th century mediums were discovered to be engaged in fraud. While advocates of mediumship claim that their experiences are genuine, the Encyclopædia Britannica article on spiritualism notes in reference to a case in the 19th century that "...one by one, the Spiritualist mediums were discovered to be engaged in fraud, sometimes employing the techniques of stage magicians in their attempts to convince people of their clairvoyant powers." The article also notes that "the exposure of widespread fraud within the spiritualist movement severely damaged its reputation and pushed it to the fringes of society in the United States."
“Hi, this is Natalie. How can I help you?” I asked, unable to give the recommended opening for fear it would be held against me in my next life. “Hi Natalie,” the caller said. “I want to see what’s going on in my relationship in general.” I asked “Cindy” to think about her boyfriend while I shuffled the cards and did the spread. Things looked bleak—among her cards were the devil and death, and the final outcome card was the 10 of swords, described in my deck as the card of “ruin.” I wondered how to break this to Cindy, particularly since I hadn’t a clue as to what was really going on in her relationship. I blithered for a few minutes about her concerns that she was investing a lot in a relationship she was worried was going to eventually hurt her. Then Cindy started talking. She said her relationship was very good, and they’ve been talking about marriage for two years, but according to her boyfriend, the time was never right. It soon became clear that she didn’t care what the cards said; she just wanted someone to talk to.
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.