The surveillance of ordinary people is far greater than I would have imagined and far greater than the American public has been able to debate.

The NSA is forbidden to 'target' American citizens, green-card holders or companies for surveillance without an individual warrant from a judge.

Snowden grants that NSA employees by and large believe in their mission and trust the agency to handle the secrets it takes from ordinary people - deliberately, in the case of bulk records collection, and 'incidentally,' when the content of American phone calls and e-mails are swept into NSA systems along with foreign targets.

Ordinary Geiger counters, worn on belt clips and resembling pagers, have been in use by the U.S. Customs Service for years.

Governors normally have jurisdiction over public health emergencies, but a widespread biological attack would cross state boundaries.

For political and bureaucratic reasons, governments at all levels are telling far less to the public than to insiders about how to prepare for and behave in the initial chaos of a mass-casualty event.