Chinese consumers are being warned to watch out for fake walnuts. Scam artists are apparently taking empty walnut shells, stuffing them with bits of concrete and paper, gluing the shells back together, and then selling them as real walnuts. [treehugger.com, ministryoftofu.com]
It seems like a very labor-intensive way to make what can't be a lot of money. But I guess it's enough money to make it a profitable scam.