Some air bases use a network of these sensors and compare their readings, to cut down on false warnings.

It broke down often, failed to identify lethal pathogens and sometimes gave false warnings when no danger existed.

Still, the risks and costs of false warnings are high.

In 1929, there were several sharp breaks, each a false warning.

American leaders still have satellite warning systems to prevent accidental launches when other systems give false warnings.

Because much of Alaska's terrain is highly variable, bush pilots will often de-activate the system, as it issues many false warnings.

While it is not clear which one of these groups did so, they gave the false warning without telling the others, who promptly fled.

Since 2.6.33-rc1, the kernel uses instead of to avoid false warnings.

No doubt they will spend tens of millions of dollars trying to swamp the public with the same false warnings.

A resident of southwest Baltimore was arrested that night and accused of giving the police a false warning.