SEATTLE — Environmental goals about garbage in this and other like-minded cities increasingly come down to three words: Throw less away. So Seattle residents are given different bins to put out on the curb — one for yard and food waste, another for recycling — and are encouraged to use ever-tinier cans for the stuff that really is trash.

The rules were given teeth this year, when Seattle became one of the first cities in the nation to penalize residents for sorting poorly. If, on inspection, more than 10 percent of a garbage can’s contents should have properly been in another kind of bin, the trash collector can pin a bright red tag on the offender’s receptacle. Financial penalties have been authorized but not yet levied. A primary goal of the policy is to keep people from throwing food and recyclable materials into trash cans.

This week, a group of Seattle residents — while stressing that they agreed with the city’s goals — said the inspections violated their privacy, as protected by the Washington State Constitution. What people toss away, the group argued in a lawsuit filed on Thursday, is still theirs to protect, however much, especially in these warm days of summer and rot, they might want to get rid of it all as soon as possible.

“This case is not about composting — this is about tossing our privacy rights in the garbage,” said Sally Oljar, 60, a graphic designer and one of the plaintiffs. “An admirable goal does not justify a bad policy,” she added.