The business on: Carl Icahn, activist shareholder

Don't you mean 'corporate raider'?

My, you have a long memory. Haven't you heard that the corporate raiders, which business loved to hate in the Eighties, have been rebranded now? Their activism is about bringing efficiency to bloated companies run by complacent managers.

So you do mean corporate raider Mr Icahn was one of the first and one of the most ferocious – and was the template for the character Gordon "Greed is Good" Gekko in Oliver Stone's film Wall Street.

Ouch. That's a bad rep to have

Don't worry, Mr Icahn revels in it. Even his mother called him Genghis Khan. He has pictures of bloody battles on the walls of his Manhattan office. Others might be long retired at 74, or after amassing $10.5bn ($6.8bn), but a lust for combat keeps Mr Icahn going.

And he is engaged in battle now?

A particularly vicious one. He is trying to take control of Lions Gate Entertainment, the movie studio behind Precious. Shareholders turned down his offer and now the company has resorted to a poison pill defence, issuing stock to a sympathetic board member, Mark Rachesky.

That must make Mr Icahn choke

More than you realise. Mr Rachesky was his right-hand man for several years. Mr Icahn promised to sue Lions Gate yesterday, accusing it of "scorched-earth tactics executed with other people's money".

He always gets his way, right? Far from it. In recent years Mr Icahn has been more famous for his disappointments. He forced his way on to the Yahoo board after it turned down Microsoft's takeover bid, but failed to get the company to sell itself. Time Warner resisted his pressure to break itself up. And just this month Donald Trump beat him in a bid battle for three Atlantic City casinos.

Poor thing

Not poor. Even if he doesn't get the shake-up he demands, his presence alone can be enough to boost a share price. And he has tapped a lucrative line in distressed debt investing recently, netting $1.3bn last year. That is money worth fighting for.