Social media has become hugely important in modern society.
For young people, in particular, it offers by far the most important means of communication and source of information.
Whether it be bullying at school, or concerns about privacy, or interference in elections, its influence is felt everywhere – and not always for the good.
Read more: Bryan Gould: Jacinda Ardern breathes new life into Commonwealth
Bryan Gould: A budget surplus takes spending out of the economy
Bryan Gould - Change of government hard for winners, harder for defeated
Political parties, in particular, have not been slow to realise that social media offers a cheap and effective means of influencing opinion; it is even argued that information gleaned from followers of Facebook and then organised and utilised by the firm Cambridge Analytica helped to determine the outcome of the election that produced President Trump.
This kind of intervention in the democratic process may cause concern but – apart from the unauthorised misuse of what was assumed to be private information – the pitching to voters on the basis of what they themselves tell us through social media about their views and preferences is not necessarily any different in principle from the use of more conventional means to appeal to them on the basis of their known or assumed views and to persuade them to vote one way rather than another.
It is less easy, however, to be relaxed about another recent instance of the political impact that social media can have. It can all too easily become the vehicle of a campaign that uses innuendo and scuttlebutt to discredit a politician or his or her associates.
The damage that can be done by such a campaign is magnified by the sheer volume and wide reach of misinformation that can be generated over a brief period – and the absence of any actual substance in that misinformation can be camouflaged by constant repetition.
The recent campaign of which the Prime Minister's partner has been a victim was just such an instance. As she and he have discovered, there is virtually no defence against such an unprincipled attack.
While, in my opinion, there can be no doubt that the campaign is politically motivated (why else was it carried out?) and is an example of "dirty politics", the absence of any identifiable central direction makes it difficult, if not impossible, to stop it or disprove it at its source. It is truly a hydra-headed monster.
A social media campaign of this type, in other words, is an ideal instrument for those who wish to inflict maximum damage while minimising the chance of detection.
It builds its own momentum, as those who had no part in launching it nevertheless see the chance to "hitch a ride", and to increase the damage it does. The planners and originators can simply disappear back into the woodwork, as others misguidedly carry it forward.
There would be nothing easier than for a couple of enthusiasts to launch a campaign on behalf of a political organisation and then allow their fellow enthusiasts to jump on the bandwagon and push it along, all without any apparent central direction or encouragement.
The calumny circulated is designed to do political damage but that is not, of course, the end of the damage that can be achieved.
The emotional distress and distraction suffered by the victims are all part of the price that is paid – and when they complain, quite legitimately, about "dirty politics" they are advised to harden up, or criticised for giving the story more legs, or are accused of bad-mouthing their opponents in identifying them as the obvious beneficiaries and culprits.
But, if the campaign is "dirty" (as it certainly is) and if it has an obviously political purpose (as it has), why can it not be characterised as "dirty politics"?
The phenomenon is not exactly unknown in our politics; some senior (and current) political practitioners, indeed, have been known to glory in and boast of their prowess in the black arts.
They have, it is true, been warned against using such tactics, but the victims – and the wider public – are surely entitled to draw their own conclusions.