Considering that receiving "unsolicited" seeds from just about anywhere else has exactly the same risk and is entirely legal, this seems to me to be little more than anti-China fearmongering. I've been asking my local state reps to stop the sale of Callery Pear trees (which are invasive and damaging) but they have ignored me for years because the nursereys make a lot of money from them and lobby to keep them legal. Perhaps if I started pointing out that the trees are Chinese/Vietnamese in origin I might get somewhere now.