Karen, you're right about Big Ag being a threat to small farmers and a free market in food. In addition to the use of the FDA etc., another very insidious tactic is the use of the patent system to attack small competitors—perversely, in the name of "capitalism" and "private property" rights. In a recent case, the Court of Appeals for the Federal Circuit held that even though the practice of saving seeds after a harvest to plant the next season is as old as farming itself, you can’t save patented seeds.
And in the case Monsanto Canada Inc. v. Schmeiser, the Canadian Supreme Court ruled that growing genetically modified plants constitutes a "use" of the patented invention of genetically modified plant cells. In this case, a farmer had his canola contaminated with RoundUp Ready canola. He saved the canola and used it for next year, but then Monsanto went after him and the farmer ended up having to destroy all his seeds. (Naturally, Monsanto is opposed to patent reform that might reduce the damage patents do.)
The rising forces of IP Police are already shutting down websites (ICE seizures; see this example), and are planning other measures to pursue "rogue websites," as well as engaging in all manner of censorship on behalf of Hollywood and Big Music, and now using patents to stop farmers from saving seeds or from growing crops even if the crops are contaminated by the wind blowing in seeds from Big Ag patented crops. What a travesty. Capitalism, this ain't.
(For more see my post The Evil of Patenting Food and Seeds.)