MSNBC policy requires journalists to report any potential conflict of interest and to seek approval from the president of NBC News before making any political contribution.

Both CNN and NPR prohibit political activity by all journalists, no matter their assignment.

A CBS spokesman said the network's policy was tightened in September 2006 to forbid contributions to political campaigns. Previously, there was a bit of wiggle room.

ABC forbids political activity by journalists.

After Huguette Clark died in 2011 at age 104, 19 relatives challenged her will, claiming she was mentally ill and had been defrauded by her nurse, attorney and accountant.

America's schools and streets are safer than Americans know.

Disclosure of private e-mails from government officials has been a legal issue in many states.

State courts usually rule that correspondence between government officials, about government business, are public records, whether they use their government e-mail accounts or private ones.

Todd Palin's frequent presence in the governor's office led some in Juneau to call him the 'Shadow Governor.' But it had never been clear, at least to the public, what roles he played.

At one point, Sarah Palin sent her husband instructions to stock up on 'fresh fruit and veggies' for the kids, and 'as little processed foods as possible.'

American nuclear reactors are well into middle age. The median age of an operating reactor in the U.S. is 34 years, placing start-up in midst of the Carter administration.

More than 30 of America's 100 nuclear power reactors have the same brand of General Electric reactors or containment system used in Fukushima.

Nuclear power plants built in the areas usually thought of as earthquake zones, such as the California coastline, have a surprisingly low risk of damage from those earthquakes. Why? They built anticipating a major quake.

Each year, at the typical nuclear reactor in the U.S., there's a 1 in 74,176 chance of an earthquake strong enough to cause damage to the reactor's core, which could expose the public to radiation. No tsunami required.

What are the odds that a nuclear emergency like the one at Fukushima Dai-ichi could happen in the central or eastern United States? They'd have to be astronomical, right?

In Montana, where Sen. William Andrews Clark made his fortune and lost his reputation, people had assumed that all his children were long dead. After all, he was born in 1839 and was of age to serve in the Civil War.

Lie detectors sometimes work because people believe they work, deterring the wrong people from applying for jobs in the first place, or prompting admissions of guilt during interrogations.

The term 'triage' normally means deciding who gets attention first.

Polygraphs are not allowed as evidence in most U.S. courts, but they're routinely used in police investigations, and the Defense Department relies heavily on them for security screening.

Polygraphs have sparked a fierce debate for at least a century.

The Iraq war fueled distrust of the press from both sides.

Because appearing to be fair is part of being fair, most mainstream news organizations discourage marching for causes, displaying political bumper stickers or giving cash to candidates.

There's a longstanding tradition that journalists don't cheer in the press box. They have opinions, like anyone else, but they are expected to keep those opinions out of their work.

Firefighters go where they're needed, sometimes ignoring the dangers even when no one is inside a burning building to be saved.