It’s not Quixtar

But the “motivational”/tool scam organization that he belongs to that’s the problem. Showing him “negative” info, like what’s on this site will not work. The best thing to do is ask questions. Steer those questions about profitablility of his business and whether or not the tapes, books or functions really help him do that. What they neglect to tell your son is that money is made through the sale of products through the Quixtar site. They push recruitment so that there will be more people to brainwash into buying tools and attending functions. The next time he tries to push a tape or function on you, just ask to see the latest catalog.
Ask him who he makes the most money off of, customers, members or downline. And always ask him why he got into the business. Putting down the business or the oraganization will only push him farther away. Be patient. Always tell your son that you love him and care for him no matter what.