. >> melinda hague is -- melinda haag is the u.s.ttorney for california. >> people are using the cover of medical marijuana to make enormous amounts of money, in short to engage in drug trafficking. >> >> reporter: medical marijuana has been legal in california. 15 other states have similar law, but marijuana remains illegal under federal law. now federal officials have sent letters to dozens of california growers and dispensaries warning them to shut down or risk arrest or property seizure. lynette shaw has been given 45 days to shut down the dispensary she's run for 45 years. >> it's so mean and inhumane that i'm broken-hearted and appalled and shocked, and i'm righteously indignant. >> reporter: shaw who operates in fairfax, a northern california town of about 8,000, says she doesn't just help the sick, she pays taxes. >> we're the number-three sales tax contributor to our town. we are a very good resource for the community. lawyer but federal officials say under the guise of providing medicine, california has become a source of m