Yes, I agree. In the tropical areas of Australia, guerilla growers plant out among Lantana, which has a very similar photo-spectrum to Cannabis. You should also note that satellites have sophisticated spectrum imaging ability.
I know it sounds like an Orwellian nightmare, but you can never be too careful these days, as Big Brother has some very sophisticated technology.
ps. growers in the US who grow in warm temperate, sub-tropical, or tropical climates would be well served to explore plant nurseries for Lantana. It is a great plant to disguise cannabis with.