Outlook Billionaire Thomas Sandell is making it quite clear that it will take more than a couple of paracetamol to handle the headache he is causing for FirstGroup.
He wants the bus and train operator to spin off its US assets and concentrate on its businesses at home, and he's secured a seat at the table by building a 3 per cent stake.
So far the company has batted him away, but, undeterred, he's jumped on a plane in an attempt to foment rebellion among the companies' investors.
He might be disappointed at what he finds. He'll probably be offered coffee (it won't be very good) maybe even some lunch (ditto) and a respectful hearing. But that'll be about it.
His fellow investors will hum and ha a bit, tell him his plan is jolly interesting before going back to sleep. If he's savvy – and you don't get to be a billionaire without being that – he'll plough on. He only needs to convince a few decent sized shareholders that he's got a point to make life very difficult indeed for FirstGroup's board, which would be well advised to start working on its defence.
According to Linklaters, the law firm which has been monitoring these things, activism is rising rapidly. They're making hay largely because traditional investors are so idle, content to sit quietly by while the businesses in which they invest grapple with the likes of Mr Sandell.
Some of the more progressive public companies have been complaining about this for a while. They'd actually like to see more engagement with their shareholders, because if they can work in partnership with them they avoid situations like the one facing FirstGroup, not to mention a host of other potential controversies.
Sadly, all too often shareholders only wake up when the battles are all but over and the activists are preparing to exit stage right with large bags of cash, their plans having succeeded, leaving others to pick up the pieces.