Unknown to me, the AC adapters had fake UL marks on them. So, the CBP seized the shipment. I asked if they could just seize the adapters, and explained that I hadn't even asked for UL listed adapters. No dice. The adapters represented less than 10% of the value of the shipment. Argh.
And, of course, the Chinese supplier wasn't willing to reimburse me. Now I have the adapters go in a separate shipment in case something unexpected is shipped.