A sidewalk in Paris, a café terrace, a red light that takes too long to turn green. The action is almost automatic: one takes a last puff, crushes the cigarette butt with the toe of one's shoe or rolls it slightly with a finger toward the gutter. No one lingers, no one turns back. Each year, the Paris cleanliness services collect about 2 billion cigarette butts, or nearly 350 tons of waste. A single cigarette butt can contaminate up to 500 liters of water and kill half of the fish in a liter of water within 96 hours. In response to this problem, Paris has launched a ten-measure plan including fines of 135 euros, distribution of pocket ashtrays, and markings saying "Here begins the Seine." The phenomenon goes beyond Paris: the entire country collects between 20,000 and 25,000 tons of cigarette butts each year. It is estimated that 60 percent of cigarettes smoked in public spaces end up simply on the ground, due to the lack of an ashtray within reach or simply out of habit. Multiplied by millions of smokers and hundreds of millions of cigarettes consumed each year in the capital, this practice generates a colossal volume of waste, which the City of Paris estimates at 4 to 5 million cigarette butts collected each day by its cleaning agents. The cost of this cleaning is not trivial either: it represents about 10 million euros per year for the community. A cigarette butt is not just a piece of paper and tobacco consumed. It is a concentration of chemical substances, since it contains about 4000, some of which are particularly toxic to living organisms. The filter, often perceived as a simple piece of harmless cotton, is in fact made of cellulose acetate, a plastic that takes years to degrade in nature. When it rains, water runs over the sidewalks, carries the cigarette butts to the drains, and then to the waterways. As part of its anti-cigarette plan, it has installed metal nails engraved with the message "Here begins the Seine" on the sidewalks, just in front of the drains, in 177 targeted areas in the capital. Paris is only the visible part of a problem at the national level. Although the capital logically concentrates a large part of the attention, due to its population density and its status as a tourist showcase, it is in reality only an example among others. Marseille Provence Métropole collects about 500 million cigarette butts per year, Bordeaux around 200 million, or 35 tons, while Lille and Nantes show respectively 100 million and 60 million cigarette butts collected annually. At the scale of the entire country, it is estimated that the country sees between 20,000 and 25,000 tons of cigarette butts disappear from the ground each year. In response to this assessment, the public authorities have begun to act on several fronts. Since the Agec law of February 10, 2020, which came into effect on January 1, 2021, an extended producer responsibility chain has been established for cigarette butts, which means that tobacco manufacturers now financially participate in the cost of collection. In Paris, throwing a cigarette butt on the ground is fined 135 euros, and 400,000 pocket ashtrays have been distributed free of charge in partnership with the eco-organization Alcome and the tobacco shops of the capital. This municipal plan is part of a broader objective, that of reducing by 100,000 tons the waste produced by the city by 2030.