That kind of behaviour - whether genuine or the result of some automated system - is raising questions about Facebook's usefulness as a platform where businesses can engage with consumers.

BBC: Facebook acts on fake ��likes��

The system can distinguish between types of behaviour and incoming information, says Dr Horvitz.

ECONOMIST: Computing

It means some computers could interpret '00' as 1900 instead of 2000, causing system failure or unpredictable behaviour.

BBC: UK opens Y2K bug website

But if a firm can tell them what its employees care about, economists are well equipped to craft a compensation system that encourages the right kinds of behaviour.

ECONOMIST: s as gurus

Litte called for Amazon to change its review system to help stamp out some of the bad behaviour of the time.

FORBES: Reviews Redux: Let's Up The Ante

It is the UN system's authoritative voice on the state and behaviour of the Earth's atmosphere, its interaction with the oceans, the climate it produces and the resulting distribution of water resources.

UNESCO: CULTURE

Its behaviour management system, developed in-house, is to be made available to local high schools by means of an open source licence.

BBC: Schools' computer costs have been rising

He said the health system could not cope with the Aids crisis and Malawians should the scourge by discouraging the kind of behaviour that helps the spread of the disease.

BBC: Funeral of Aids patient in Zambia