Crowdsourcing provides the ability to accomplish information-gathering tasks that require the involvement of a large number of people, often across wide-spread geographies, expertise, or interests.
However, researchers from the University of Southampton and the National Information and Communications Technology Australia (NICTA) found that a significant feature of crowdsourcing - its openness of entry - makes it vulnerable to malicious behaviour.
They observed such behaviour in a number of recent popular crowdsourcing competitions, through analysis based on the 'Prisoner's Dilemma' scenario, which shows why two purely 'rational' individuals might not cooperate, even if it appears that it is in their best interest.
"At the same time, the openness makes crowdsourcing solutions vulnerable to malicious behaviour of other interested parties. Malicious behaviour can take many forms, ranging from sabotaging problem progress to submitting misinformation. This comes to the front in crowdsourcing contests where a single winner takes the prize," said Naroditskiy.
Surprisingly, making the attacks more expensive for the attacker is not an effective way of deterring them.