Never let it be said that cannabis smokers can barely find enough energy to make their once-daily trip to the garage for crisps and chocolate milk: thanks to the weedheads of Australia, we now know that their habit is synonymous with artistry and digital activism on a truly industrial scale.

On Instagram, you will find thousands of pictures documenting cannabis use in all its fascinating glory. Such subtle hashtags as "cannabis", "marijuana" and "weed" flag up photos of buds, bongs, towering home-grown plants, joints the size of baseball bats (obligatory, obviously), and scores of dead-eyed weed enthusiasts in the act of partaking.

As a result, two things have happened. First, a whole knuckle-headed subculture has grown around the snaps, perfectly crystallised by a scintillating blog entry from back in March titled The 20 Hottest #Girlswhosmokeweed on Instagram I've found (so far) and tweeted over 7,000 times. Second, there have been threats from the authorities in Victoria to somehow pursue anyone who has posted such images – which, predictably enough, have only accelerated the craze further.

At which point, it is worth pausing for thought, and marvelling at the stupidity of it all. Of course, the state getting in such a lather about cannabis use only underlines the lunacy of its prohibition – as with this week's Guardian story about weed-trade-related violence and shootings, complete with a senior cop in Merseyside advocating harsher sentencing for those who grow and sell it. Both stories flag up much the same organised idiocy: the Melbourne-based Herald Sun quotes police warning that "anyone who posts images of this nature may find themselves subject to a criminal investigation"; assistant chief constable Andy Ward thunders that "the amount of money being made by criminals should be reflected in the sentencing". Shades, as always, of Chicago circa 1925, a colossal waste of human effort – and, all too often, utterly needless gangsterism.

That much surely ought to be accepted by anyone even halfway rational. But at the same time, the Australian Instagram hoo-hah also points up marijuana's real dangers – which, for most of its users, are less a matter of psychosis and mental breakdown, than induction into a culture of narcissistic tedium. Once you're in, it is very hard to escape: if you're not careful, as well as your daily motivation crashing to the point that even the aforementioned crisps and chocolate milk become a stretch, you will find yourself boxed in by a great wall of novelty cigarette papers, "amusing" stash tins and equally entertaining water-pipes. Worse, weed may well end up being all you talk about, in much the same way that real ale enthusiasts go on endlessly about "hoppy brews" and "session ales", talking to no one but themselves.

In that sense, the Instagram galleries amount to a great big cautionary tale. Look at her, with her leaf-shaped tattoo! Look at him, with his presumably brain-shredding bong! Check this person out, with their ready-rolled green joints, inscribed "glamour", "love", "pain" and "lust"! And then think about the spectacle of a drug culture that does not put its chosen substance at the centre of a whole creative firmament (a la ecstasy, acid, and at a push, booze), but that worships intoxication for its own sake. Boring!

Therein, I think, lies one of the best arguments for decriminalisation – not just of the use of cannabis, but the whole industry that feeds it. Just imagine: we might thereby separate dope-smoking from the kudos that comes with illegality, convince a few Instagram-posting types that smoking weed is not interesting or sexy in any way, and thereby stop people making such a huge fuss about a substance that is, in any case, often a byword for humanity at its most myopic and useless (hash in particular has always struck me as leaden means of glueing yourself to the furniture, thinking crap music great, and finding amusement in the most banal rubbish). We can but hope: on this evidence, though, the revolution is not about to start in Australia.