i can't agree with you more...........caution is always a good idea with
ANY type of divination and seeing.
i was doing a tarot party, years ago, at a house and the father who had passed on some time before, well, his stuff was all over in the basement. boxes and boxes of his stuff. that's where they had the table set up for me to do the party..........
he entered my cards and it was years before i finally got them to read again. they would only read the past......like 5 years ago, for many years. it wouldn't have happened if i had cast a circle or used reiki to cast a circle before using them.

in light,
jade