How many times have you endured yet another preachy public-service announcement and thought, Oh, shut the hell up? The American Legacy Foundation takes earnestness fatigue to heart with its new series of low-key TV spots and companion print ads. In “The Truth,” kids hold up Jenny Holzer-style LED signboards displaying numbers surrounded by superimposed sentences: EVERY 8 SECONDS, BIG TOBACCO LOSES ANOTHER CUSTOMER. THEY DIE. The teens never utter a word, and you hear nothing but ambient sound, like the creak and roar of a nearby roller coaster. Legacy, created in 1998 through a massive settlement between 46 states and tobacco companies, used to be a lot noisier about “The Truth.” Earlier spots used a-bit-too-familiar ad parodies – think Saturday Night Live – to drive home the deadliness of smoking. Now, by draining all the humor and affect out of the campaign, “The Truth” has gained an unsettling edge. In magazines like Rolling Stone and Spin, its grainy, snapshot quality stands out among all the glossy, overstyled ads. And even if you’re only half-watching, the eerily wordless TV spots cause you to suddenly look up to see what all the quiet is about. Kids may not be able to handle “The Truth,” but this time around they can’t ignore it.