anna werner, cbs news, san francisco. >>> tiktok is suing the federal government to block a law that force a nationwide ban of the video-sharing app. what it does is sets up a legal battle pitting national security concerns against the free speech rights of tiktok users in the u.s. if tiktok loses, it could be kicked out at app stores unless its chinese parent company sells within a year. >>> some passengers aboard a delta flight that landed in seattle last night had to exit the plane on the emergency chute after a small fire broke out near the nose of the plane. delta says flames were reported ater the flight arrived from cancun and the plane was plugged into electric power. no one was hurt. >>> tonight we go in depth on the campus protest that prompted the campus protest that prompted usc to cancel its main [stomach growling] it's nothing... sounds like something. ♪when you have nausea, heartburn, indigestion♪ ♪upset stomach, diarrhea♪ pepto bismol coats and soothes for fast relief when you need it most. did you know... 80% of women are struggling with hair damage? just like i was.

anna werner, cbs news, san francisco. >> norah: tiktok fights back against a potential u.s. ban. could mean for the 170 million americans who use the tiktok app. ♪ ♪ he can stay undetectable with fewer medicines. that's why he switched to dovato. dovato is a complete hiv treatment for some adults. no other complete hiv pill uses fewer medicines to help keep you undetectable than dovato. detect this: leo learned that most hiv pills contain 3 or 4 medicines. dovato is as effective with just 2. if you have hepatitis b, don't stop dovato without talking to your doctor. don't take dovato if you're allergic to its ingredients or taking dofetilide. this can cause serious or life-threatening side effects. if you have a rash or allergic reaction symptoms, stop dovato and get medical help right away. serious or life-threatening lactic acid buildup and liver problems can occur. tell your doctor if you have kidney or liver problems, or if you are pregnant, breastfeeding, or considering pregnancy. dovato may harm an unborn baby. most common side effects are headache, nausea, diarrhea, trouble

anna werner reports. >> like anything online, the question is what what's real and what's not.coalition for a safer web examined dozens of tiktok profiles offering to sell popular prescription weight loss drugs at lower prices. and in nearly every situation, they say it was a scam. >> come check this. >> reporter: look at some of the videos researchers found. scammers say say flashing stacks of weight loss drugs, supposedly selling those popular drugs at a low cost without a prescription, sometimes using people's testimonials. >> hey, guys, i'm doing my first mounjaro shot. >> reporter: along with before and after photos showing fabulous results. one video featuring a supposed customer's comment, "great product, fast shipping, and i lost 16 pounds already." but the researchers say all of those videos were actually scams to lure in vulnerable buyers. the digital citizen's alliance tom galvin. >> as we search for them, over time because of tiktok's algorithm, they began to search for us. so it's not hard to find several dozen operators offering ozempic. in every case that we foun

anna werner, cbs news, san francisco. >>> police and sheriff's departments are contactually upgradingir weapons. cbs news partnered with nonprofit news stations to look into this, and we discovered many of these police guns are sold and thousands end up being involved in crimes every year. stephen stock reports. >> you know, another family lost another child at the hands of a firearm that shouldn't even be on the streets. it shouldn't even be on the streets. >> reporter: candace leslie's only son died three years ago, shot four times outside his apartment. detectives gathered a gun involved in cameron brown's death but they've made no arrest. >> i'm losing trust in the people who are supposed to protect and serve us. >> reporter: but what candice didn't know, until we told her, was that a weapon involved in her son's death here in indianapolis was a former police weapon from a sheriff's office more than 2,300 miles away. using public records, cbs news traced a gun involved in brown's death, a glock 21 handgun, to a sheriff's office in stan us las county, california. >> there's no reas

anna werner has the latest. >> reporter: it was our investigation that brought the agga device to thetained by cbs news and kff health news show several months later, the agency showed up for its first ever inspection at the device's manufacturer, johns dental laboratories, an 85-year-old company in indiana. vards these are some of the patients who told us a dental device described by its inventor as a cure for common conditions instead wrecked their mouths. >> i noticed my teeth were starting to get loose. >> i can't bite into absolutely anything. >> my front six teeth also became extremely flared outwards. all six of them -- yes, they were doing this. >> reporter: the agga was promoted as a device that could expand the upper jaw without surgery to help treat tmj problems and sleep apnea. >> it's the best kept secret in orthodontics. >> reporter: its inventor, tennessee dentist dr. steve galella, seen here in australia training dentists to use the agga in 2017. >> you could cure people of things they never thought they could be cured of. >> reporter: his device was manufactured here