Please read the following article carefully. It is about US law, but the practice could be more widespread and whether UK law on interception could protect people is questionable.
The facts are the following: honeypot (= fake website or similar created by law enforcement forces like the FBI here, to attract illegal behaviours) on child porn; Mr Vosburgh clicked on a link, did not look any further on the website, and found himself arrested by the FBI. Guilty verdict returned by jury; his lawyer tries to overturn the verdict, but chances of success are small.
I have several issues with the case:
1) in itself setting up a honeypot is not "kind of sad", contrary to what is said in the McCullagh's article. Entrapment always existed, especially for serious crime which detection causes difficulties. Nothing new here
2) entrapment is however regulated, for the obvious reason that innocent people may fall in the trap without knowingly engaging into illegal behaviours. And that's where the difficulties start. To click to a porn website cannot constitute a crime in itself if mens rea, intent to go to a porn website, does not exist. Mens rea cannot be deducted from the simple action of clicking. Anybody who used the internet knows how sometimes we end up on a website we surely never intended to go, for its contents does not reflect our original search. Therefore, I found it troublesome that the FBI relied on evidence based solely on clicking. The least that we can say is that evidence gathered by entrapment is never sufficient; other corroborative evidence must be brought. According to the article, it does not seem the case. In other words, by not engaging into other investigations that could corrobate the clicking action as proof of looking at child porn, the FBI simply did not investigate the case of the alleged offender. And this is more than troublesome. The life of this person found guilty is shattered until his death: if the conviction is not overturned, he will never find employment again in academia (and he is a PhD student; think of the amount of money one has to pay to do a 3 to 4 years PhD - you have to be wealthy or borrow a lot of money), and will be systematically stigmatised for something that looks like he has never done.
Last thing, even if he was interested in child porn, that simple fact NEVER discharges the prosecution to prove beyond reasonable doubt that the person engaged in the illegal activity. If it were, we would simply live in a dictatorship, like it used to be in the USSR where one could be found guilty and send to the goulag for "unauthorised thoughts". Criminal procedure is far too serious a matter to be played with simply because we think we are morally on the right side. Reading this article on Good Friday just reminds me that whether one believes or not in Jesus Christ, the story of Good Friday is there to remind us of our "dark side", what we tend to do when we think we are right. Agree: striking the balance is not easy; but criminal procedure is about finding that balance, not denying it per se.
M. Masnick "Click This Link, Go To Jail" (20 March 2008)
D. McCullagh "FBI posts fake hyperlinks to snare child porn suspects" (20 March 2008)