Open data creates pitfalls as well as opportunities

David J Hand

In 2005, the web developer Adrian Holovaty launched www.chicagocrime.org, which combined data released by the Chicago police department with Google maps to show where in the city crimes were occurring. ‘Crime maps’ have since been extended to many other cities, where they help the police to allocate resources and enable the public to identify risky areas.

The Galaxy Zoo project has enlisted web surfers to identify images taken by the Hubble telescope since 2010. And The Guardian launched a crowd-sourcing effort in 2009 in which more than 30,000 people have combed nearly a quarter of a million pages of MPs’ expense claims.