The pin and pattern spotting system did less well when it was applied to data gathered when users were walking around with gadgets.

BBC: Smartphone sensors reveal security secrets

Meanwhile, in the two under-river tubes that cross between Exchange Place and the World Trade Center, PATH workers have jury-rigged a system of walkie-talkies and train-spotting staffers to get service there running at all.

WSJ: PATH's Road Back Is Rocky

The new system will, however, be ideally suited for spotting tourists or students who overstay on their visas, but that is a trivial issue.

ECONOMIST: BIOMETRICS

All regulators, and especially the Federal Reserve, were accused of failing to identify the housing market bubble that preceded the financial crisis, and the new council will be charged with spotting such a build-up of risk in the financial system in future.

BBC: Q&A: US Senate's banking regulation bill

As word-spotting systems spread, call-centre training schools have started coaching students in gaming the system so they look good under the additional scrutiny.

ECONOMIST: Monitor