Thanks to the wide availability of public records in digital form in the United States, some journalists there have long used “database journalism” or “computer-assisted reporting” (CAR) to produce sophisticated stories based on snippets of information drawn from public databases.

Unfortunatly, this type of investigative journalism that has been slow to catch on in Britain, despite the greater availably of public data through the Freedom of Information Act.

One type of CAR story that has become common in the United States — the surveillance of sex offenders listed on public registers introduced since the mid-1990s under “Megan’s Law” legislation.

Several local papers and television stations across the United States have used the GIS mapping software Arcview to uncover sex offenders who were living closer to schools than local law allows. Other reporters have compared registers with databases of public employees to uncover sex offenders working in schools, hospitals, and nursing homes.

If an equivalent “Sarah’s Law” were introduced in Britain, stories similar to these might one day also become possible in the UK.

But writing in Germany’s Süddeutsche Zeitung, Lars-Marten Nagel recently examined the ethical implications of these stories. Do such stories effectively deputise journalists into law enforcement?

No, say the journalists: these are public interest stories that aim to uncover incompetence in law enforcement or the absurdities of some of the laws’ provisions.

But Nagel also quotes one journalist who worries that his stories might drive sex offenders underground.

A spokeswoman from the Association for the Treatment of Sexual Abusers, meanwhile, warns that media accounts often provide a false image of sex offenders as and risks provoking vigilantism against them.

The protests reported in Britain in 2000 after the News of the World started “naming and shaming” alleged paedophiles are an example of how such stories can have undesirable consequences, she said.