The aim was to stir up a political storm over privacy that would make it harder for Google to establish its own social media offer.
The revelation provoked hand wringing and remorse, but to me the surprise is that anyone is surprised.
The dark arts were not invented by JK Rowling for the education of Harry Potter. In the 40 years I have been exposed to financial and business PR, the potential for dirty tricks has always lurked there in the background. One should not condone it, but it is disingenuous to pretend otherwise.
Just a few weeks ago I had lunch with one low-profile firm that is doing well out of London's developing position as divorce capital of the world. Its speciality is to be employed by one party in the divorce to dig up dirt on the other and get it placed in the papers. Think of all those cases where the 'background' on defendants has been far more colourful and extensive than has been revealed in court.
In many high profile takeover battles, it is routine for the PR to retain a private investigation firm to sift through the background of the executives on the other side. One of the biggest British takeover battles of its time was won by discrediting the chief executive of the other side by leaking that he had lied in his Who's Who entry about going to Harvard.
Every so often it got out of hand, as with the fight for control of Harrods between Mohammed Al Fayed and Tiny Rowland of Lonrho. But these were controversial more for the scale of the activity and the sin of getting caught than for the underlying principle. The industry has since learned to be more discreet, but these days you are likely to find similar mischief in deals to do with Russians, mining or big government contracts.
And this leads to a more general point. Successful businesspeople are rarely without ego. It is not enough for them to be seen to succeed; their competitors have also to be seen to fail.
Anthony Hilton is City commentator on London's Evening Standard