I've never had the pleasure but ubiquitous "rebel investor" Carl Icahn would appear to be a man difficult to love. Rarely guilty of the sin of being backward in coming forward, Icahn has been in characteristically bombastic form of late in his demands of the Yahoo board in its protracted attempts to fend off Microsoft's embrace.

The thing is though, he's right.

You don't have to be Warren Buffett to work out that Yahoo has long been charting a direct route towards the unattractive region of Nowhere Fast. Changes of management and an expensively overhauled ad network have done nothing to fix things. Microsoft offered a huge multiple, the opportunity to achieve vast economies of scale and roll a market number-two and number-three together to shoot at the number one, Google.

It might not have been a subtle plan but, with the G-men disappearing out of sight in internet advertising and search, it was worth a shot at clawing back share in possibly the most lucrative growth market the world will offer over the next decade at least. Yahoo boss Jerry Yang turned the deal down and didn't even consult his shareholders.

Yang should sell and be done - or Icahn might well do it for him.