This was an interesting posit from Open Mike:

This is like the cops being afraid to raid meth labe
for fear of the armed , "under the influence" culprits,
bad dogs, etc, so pester peaceful gardeners instead
because it is less dangerous, therfore safer for the cops.

The bong thing was a rarity, the only one I can remember. I'd rather bust a heroin dealer, but we can't always specialize. The fact is, we raided a meth lab the next day, as we do about once or twice a week. However, the most dangerous thing we do is raid marijuana dealers. All told, the marijuana dealers are significantly more vicious than heroin, meth or cocaine dealers. We seize more guns from marijuana dealers than from all the other types of dealers combined. Around here, when a cop is shot dring a drug raid, it's usually a marijuana dealer.

I think there are several reasons for this. I have observed that people who regularly smoke marijuana tend to have the emotional maturity of a spoiled twelve year old. Combine that with the "hemp culture" mentality and a lot of High Times indoctrination and the result is one dangerous individual who thinks he's defending his gods-given right to do anything he wants to. I think the clearest illustration of this type of mentality is somebody we all know and love, by golly, it's Conspiracy GUEST!

Imagine having Conspiracy GUEST sitting in his living room under several thousand watt grow lamps, surrounded by ten thousand dollars worth of thickly budded sinsemilla, with a huge chunk of currency in the false floor of the closet. It might be enough to make him paranoid or something.

Peaceful gardeners my ass.