This just posted by AP:
Federal officials are warning California medical marijuana dispensaries they must shut down within 45 days or face criminal prosecution and having their property confiscated. The state's four U.S. attorneys sent letters Wednesday and Thursday notifying at least 16 pot shops or their landlords that they are violating federal drug laws, even though medical marijuana is legal in California. The attorneys are to announce their coordinated crackdown at a Friday news conference.
We'll see how it all sorts out, but such a crackdown could be a killer for the fledgling dispensary business, which already has been facing lots of pushback from local governments. (Even L.A., which at first largely ignored the influx of dispensaries, has been trying to reduce the number of operators.) Another big problem: the IRS. Business deductions are being turned down by the government because the dispensaries are considered to traffic in illegal drugs.