Defenders of the court ruling would argue that there was nothing defensible about the content of the chat logs, which pertained to “explicit conversation concerning incestuous, sadistic paedophil[ic] sex acts on young and very young children".
Surely this is no more than a minor change in the law having little effect on anyone who is not themselves a dangerous paedophile?
Initially, the legal reaction was that such a case could not possibly succeed - and that was pretty much the view of the judge who threw it out when first it arrived at Maidstone Crown Court in November 2011.
But that was before an appeal brought by the prosecution in February of this year, and the appeal court ruling in which three appeal judges - Lord Justice Richards, Mr Justice Kenneth Parker and Mr Justice Lindblom - ruled unequivocally that publication to an individual did fall within the meaning of the OPA.
The idea that one could be criminalised for possession of an image of an act that was itself lawful to carry out first emerged in respect of child abuse law – when it became a criminal offence to possess a picture of a 16- or 17-year-old engaged in sexual activity – and was then extended significantly with legislation on extreme porn.
The latter, initially forecast by its proponents to lead to no more than 30 or so cases a year, last year notched up over 1,300 prosecutions - and an unknown number of cautions.
For all that, the CPS still maintains a list online of things THEY believe would attract a jury's disapproval.
During its long history it has been used to prosecute novels and images, invoked by the police seizing pornographic magazines and on one infamous occasion, tested out in respect of online publication - the "Girls (scream) aloud" case - though then, the audience was likely to be counted in the dozens if not hundreds.
The danger, as some may now suspect, is that the principle will, inevitably, be widened out - with the result that discussing sexual fantasy online may become increasingly perilous for those who wish to do so.
Throughout that period, the idea that it might be used to police one-to-one conversation does not seem to have figured highly in the thinking of police and prosecuting authorities.
Indeed, as previously reported in The Register, a submission by Kent Police to the consultation on the extreme porn law in 2005/6 complained that the law was insufficient and, as they submitted: "There remains a legislative gap in terms of written fantasy material specifically about child rape and murder".
Weight is added to this contention by the IWF, who have told us that while they continue to report obscene adult content, hosted within the UK and publicly available online, they would not assess what was written in "a private online conversation".
The real danger lies in the fact that the history of UK law on matters sexual over the last couple of decades is that principles first introduced to protect children are often extended over time to other areas.
You could be committing a criminal offence next time you discuss your deepest fantasies with someone online. That means it is therefore perfectly possible for the content of online chat, should a jury decide that it is capable of "depraving or corrupting", to be judged "obscene" - and as such for one or both participants in that conversation to be guilty of a criminal offence that carries a sentence of up to five years in prison, and a stint on the sex offenders' register.