The FDA banned vitamin B17 years ago, actually, in the 1980's when "World Without Cancer" was published.
Although it is banned, it is not illegal.
You Ask: What's the Difference?
The difference is ~
If any hospital uses laetrile, the law says that they jeopardize any grants from the government as well as any monies from Medicaid and other hospital insurance originating from the government. Since nearly all of hospital revenues come from patient insurance, not one hospital in the U.S. will take the chance and use any banned substance including, Amygdalin (also called vitamin B17 and Laetrile).
Any doctor that wants to use the substance from apricot pits, must have their patient fill out a form, and then the doctor must submit the form to the FDA. Again, doctors don't want to get involved in this and would rather keep their names off of the FDA lists. Additionally, the doctor's malpractice insurance will not be valid if they prescribe laetrile (B17--amygdalin) to a patient. The American Medical Association (AMA) treats any doctor that prescribes laetrile to be a renegade (traitorous) and that he has violated the AMA's membership policies and will be subject to membership termination. Therefore, any doctor that prescribes laetrile may destroy his carreer as a doctor.
Any individual that sells laetrile must not claim that it does anything in his place of business. Many health food stores in the past were raided and had to give up their supplies of B17 because the B17 was near books that claimed that the B17 was the answer to cancer. In other words the books were near the B17 in the stores and was therefore considered "labeling" which is a term used by the FDA. Labeling according to the FDA is against the law and can be prosecuted.
However, on the Internet, it is different. Internet law is tricky and not the same as U.S. commercial law. In one case, Ken Kholas took the FDA to court and won his B17 back. That court case proved it wasn't wrong for him to have or to sell it though it cost Ken's father a tremendous amount of money.
What THIS MEANS TO YOU is that you can purchase, use and have B17, and you will not have violated any law.