Marijuana is still federally illegal...med state or not, and they don't like people using their postal service to ship drug paraphenelia, let alone drug-making materials. If you get busted with even one seed, it's still possession. Having several seeds shipped to you from a seedbank can easily be an intent to manufacture/cultivate, ESPECIALLY if they were to do a controlled delivery and find your grow room after finding out how seeds are packaged because some dumbshit posts how it's done on the internet. I know it's highly unlikely...most of the time, they just intercept the package and send you the dreaded "letter," but a little paranoia never hurt anyone. They call it "stealth shipping" for a reason...it's sneaky and the only people who know are the ones that order. Yes, the feds could (and probably have) place an order, but there are several different methods of stealth shipping. Making them work/spend a little money to figure things out is way better than handing them the info via Google. As you said, "if you can think of a way to hide something, they can think of a way to find it." Well...I say make them find it...with more effort than a few simple keystrokes.
Besides, it's the media you have to worry about. You start posting how pot seeds get through customs all over the damn internet, and all of a sudden, every idiot around starts talkin/posting/blogging about it. Then Dateline NBC needs a f*cking story, and gets wind of this subject...now, it's a major national problem that needs dealt with. Mary Beth Buchanan gets involved, and tons of people go to prison. After that, stealth shipping has to evolve and the grower will pay for it OR we lose several more seeds companies' willingness to ship to the US. Many have already given up.
Nobody's gonna think you're any cooler for posting how your seeds were packaged. Nobody that matters gives a shit, because they already know. All you're doing is openly informing those who don't need to know.
If anyone wants to know how seeds are shipped, they should have to place an order.