Rachel Pelkey has seen it many times before. Working behind the counter at Grille Zone in Boston, she'll watch diners finish their meal, gather their rubbish, march it to the front of the restaurant, and then look confused.
"The biggest question I get is 'Where's the garbage?' " she says with the kind of grin a mother gives her questioning child. "I explain that we don't have a garbage can, only compost and recycling."