I've had RFI problems in the past in my own home and have taken care of them. I drove up and down my street and noticed a tremendous spike in RFI in front of 2 houses across from each other. Which one I don't know.
And yes, IF they are growing Marijuana, they are drug dealers. This is not an accusatorial statement, it would be a fact. Legal or not.
Have you read any of these medical marijuana growers forums. They speak for themselves.
Now, if the RFI is something other than this, I'm still not going to stick my nose were it don't belong until I know what the regulations are, and I am having trouble researching what the Arizona laws are that covers the certain building or operating codes that may fall into a more esoteric matter, like RFI.