A great number of products were banned in 2005.
New products were released that were not on the ban list.
The FDA has declared that some of these new products are illegal to sell REGARDLESS of whether they are on the ban list because they do not meet the government definition of "supplement" and therefore are considered "drugs" which cannot be sold without government approval.
Many well known companies abandoned sale of these new compounds because of the possible legal consequences.
Some new companies arose to continue selling new compounds.
Possession of pre-ban products is a crime. Sale of post-ban products MIGHT be a crime. Possession of post-ban products most likely isn't a crime (for a variety of constitutional reasons).
Use and/or possess at your own risk.