Until last week, if I ever thought about Sir Martin Sorrell — not an everyday or even an annual occurrence, I’ll grant you — it was in a vague sort of way: businessman, advertising agencies, massive divorce settlement, rich. Today, if I ponder the question of Sorrell, I think: “mad dwarf”. I also think of his colleague and sometime lover Daniela Weber, and the unlovely words “nympho schizo” pop into my head.

If I were Sorrell, I would find this irritating, especially if I had spent the past few days in court trying to make sure those nifty little phrases were not attached to my name for ever more. Alas! “Mad dwarf” lodges itself in the consciousness rather.

Sorrell, 62, is chief executive of WPP, the world’s second biggest advertising agency, which is worth £7.8 billion. He is worth £85m. His company had a representative in Italy, one Marco Benatti, who had a “lieutenant” called Marco Tinelli. Benatti got the sack in 2006, which he found especially annoying because his replacement was Weber, 44, his former “protégée” and an ex-lover of Sorrell’s.

Aggrieved, Benatti allegedly sent an e-mail referring to Sorrell and Weber as “the mad dwarf and the nympho schizo”; the same e-mail contained an image of the pair that was deemed “vicious” (in the European sense of “pervy”, I assume).

A couple of months later Sorrell became aware of an anonymous blog — accessible to everyone and presumably read with avid interest by those in the advertising industry — which referred to him as “Don Martino” and made allegations about criminal fraud, deception and money laundering. He decided his former colleagues were behind the blog and its allegations, and sued them both for libel and invasion of privacy.

“I found these allegations, as well as the implication that I would stoop to the most heinous of criminal activities in order to get what I want, utterly outrageous and disturbing — I felt the use of the words ‘Don Martino’ and ‘wise guy’ were intended to reinforce this impression, suggesting I had some sort of mafia connections, making me sound like a ruthless criminal. I cannot think of a more comprehensive attack on my character,” Sorrell, who is 5ft 6in, told the court.

He added that he worried about the impact the allegations would have on his children. You felt sorry for the toddlers being teased at nursery, until you realised that Sorrell’s three sons are aged 29, 31 and 32 and work for Goldman Sachs, the investment bank.

Anyway: Sorrell withdrew his High Court action last Wednesday and settled for damages of £120,000, which is the amount his former colleagues had offered before the trial began. The two Italians had denied that they were responsible for either the “vicious” e-mail or the blogs, but the case ended before their evidence could be heard. Sorrell’s costs are estimated at £2m, which is a lot of money, especially if it has not cleared your name and everyone in the country now knows you as a priapic “mad dwarf” and have been called “Don Martino”.

Which rather asks the question: is it ever worth suing for defamation, especially in the case of blogs? Those that so wound up Sorrell were read by a minority of interested parties; as a result of the court case, the allegations that he found so distasteful are now known to millions.

Meanwhile, in Paris, an English girl sacked for bringing her employers into disrepute by writing an anonymous (very good) blog called petite anglaise was awarded £30,000 for wrongful dismissal last week. A tribunal decided that Catherine Sanderson, 34, had been dismissed “without real and serious causes”.

Her former employer Dixon Wilson, the British accountancy firm, had justified her dismissal by claiming that although the blog never mentioned Sanderson’s place of work, it featured photographs of her and therefore associated her with the firm. Its lawyer also claimed that she had wasted time by blogging from work, that an entry about meeting a lover implied she might have bunked off work, and that she had endangered the company’s reputation by writing about her professional life.

I find the idea that a company should believe it owns every aspect of your life and thoughts peculiar, to put it mildly, and it is good news that this test case turned out the way it did. “I won,” Sanderson blogged last week. “A year’s salary, plus costs. I will only get this compensation if my ex-employer does not lodge an appeal . . . but right now, the principle is enough for me. Round one to petite anglaise!”

As in Sorrell’s case, it is hard to see what Dixon Wilson thought it would gain by suing Sanderson. Her blog is popular — she has got a two-book deal on the back of it — but you’d have to be enormously big-headed and/or paranoid to believe that tens of thousands of people were reading Sanderson’s musings on life, loves and family purely because they wanted to identify the accountancy firm where she worked.

Indeed, you would think an accountancy firm would be, if anything, rather delighted to have a successful blogger on its books — it’s hardly the world’s most glamorous profession. Besides, fellow accountants may have surmised the name of the company Sanderson worked for with a little detective work, but nobody else knew or cared. Today everyone knows who her petty-minded employers are. Petty-minded and out of pocket: why did they bother?

There’s nothing pleasurable about being defamed, although it comes with the territory if you’re even remotely successful. Even if you aren’t, blogs are so plentiful and, for the most part, uncensored that everyone will soon have experience of this, whether they’re an A-lister or a plumber.

Sorrell is a powerful man and his taking exception to a few gossipy rumours and an unappealing nickname just makes him look silly. He has gained absolutely nothing from his foray into the world of libel litigation — in fact he has lost a great deal, both financially and personally.

Similarly, Sanderson emerges from her own court case as the bloggers’ heroine and her former employers as silly people who ought to have better things to do.

Both these cases set an interesting precedent — if it’s simply not worth suing bloggers, will bloggers become self-moderating, or wilder and wilder in their allegations?

Either way, people like Sorrell must accept that the need for a rhino hide comes with the territory and usually suing for libel just makes you look pathetic.

india.knight@sunday-times.co.uk

Times Recommends

• Care in old age: we won’t pay, the State can’t
• Viewers’ choice: our talentless Everyman
• Memo to the poor: go forth and don’t multiply