Where someone introduces irrelevant material to the issue being discussed, so that everyone's attention is diverted away from the points made, towards a different conclusion:

"You may claim that the death penalty is an ineffective deterrent against crime -- but what about the victims of crime? How do you think surviving family members feel when they see the man who murdered their son kept in prison at their expense? Is it right that they should pay for their son's murderer to be fed and housed?"

The proper response is "Are they going to turn to a life of crime because of this?"

This comes from the practice of dragging real red herring (very smelly fish) across the trail of a fox to lure your hounds off of the scent. A hunt saboteur might resort to something like this, but since the hounds are trained using this method, it probably wouldn't work. I think Tim Curry said it best when he said, "No, no.. communism was just a red herring" at the end of Clue.

Prior to 20th century depletion of fishing stocks from over fishing, herring was a major food fish of the North Sea. Huge fishing fleets set out to catch this significant food source to feed northern Europe. Herring in particular do not keep well without refrigeration - within 24 hours they begin to deteriorate. To preserve the fish, herring were salt cured for 24 hours, then smoked on spits in chimneys for up to 48 hours. In this process, the herring turned dark red and stiff as a board. These red herrings could now be kept safely for long periods of time, requiring soaking in fresh water for softening and desalination before cooking.

Red herring were a staple in the diet of the poor, hence their contribution to the idiom neither fish nor fowl nor good red herring. Red herring were also incredibly redolent, resulting in their use, noted elsewhere, in distracting hounds from the trail of a fox.

"Red Herring" is slang for the S-1 filing, the document compiled for the Securities and Exchange Commission when a company wants to go public. It's from that slang term that the Red Herring financial magazine got its name.

Red Herring the magazine is run by Tony Perkins (not the actor) and is famous for a flip attitude and elbow-rubbing insider's perspective. It covers technology business: start-ups, established public companies, venture capital. Perkins has expanded the Red Herring business to include conferences and newsletters.

The magazine's coverage of startups got particularly tiresome during the dot-com boom, as Red Herring became a little too willing to suck up to the New Economy. During this time they hired dozens of reporters, most of whom were let go about a year later when the dot-com crash came around.

To their credit, they never completely lost their healthy skepticism. Exhibit A: Every April, they would run a special April Fool's Day article touting some glorious new start-up that didn't exist. They'd load the article with hot buzzwords and lots of tempting technobabble, and then -- this is the best part -- include a picture of the young, entrepreneurial staff. The picture was of the Red Herring editors themselves. Later, they'd print the letters from people who wanted to invest in the company or buy its products. It was hilarious. I doubt they'll continue to do it, given that the joke is out.