A little more research found this - from Seedman's blog, from an attorney, with this being a good summation
Less controversially, cannabis seeds can be purchased without too great of a legal concern if the seeds are used for non-marijuana plant producing purposes. For example, purchasing marijuana seeds for use as fishing bait, bird food, preservation or other more abstract purposes is totally legitimate. The reason why individuals may want to use cannabis seeds for less conventional purposes is due to the seeds’ high protein, amino acid, and vitamin components. All websites that sell cannabis seeds should strive to avoid the dangerous legal consequences of selling marijuana inappropriately to non-sanctioned buyers. Ultimately, like all things cannabis, there is unfortunately still a risk involved for both the buyer and the seller.
My concern would be to make the case in court that what we were selling was for the high protein content, when the websites all clearly explain Yield, height, etc. I don't think that's an arguement worth paying for in US court.