Yes Robert, but I would suggest that almost none of the people who had been charged for a reading would be intellectually or financially capable of filing a lawsuit, and those who did, and were succesful, would most likely be awarded a piddling sum compared to the money that DuFresne could make with a book or books and the lecture circuit and TV appearances.
If I was his agent, I'd be encouraging this path as being more lucrative than his pitiful attempts at psychic scammery will be, as he is so bad at it, that his mommy's loyal fanbase will soon become disgruntled and move on to a different psychic to spend their money on.
ETA: Also, it seems that money is his primary motivation, so if someone was to show him that he stood to make a lot more money from exposing his mother, and if he really is the despicable character that some people have said he is, surely he'd go for it? That would be a massive win for us. I think we should give him some friendly encouragement.