When it comes to religious terms, you would be hard pressed to find a word more misapplied by the media than "fundamentalist." As your GetReligionistas have stressed a gazillion times, that is why the term has its own cautious entry in the Associated PRess Stylebook:

“fundamentalist: The word gained usage in an early 20th century fundamentalist-modernist controversy within Protestantism. In recent years, however, fundamentalist has to a large extent taken on pejorative connotations except when applied to groups that stress strict, literal interpretations of Scripture and separation from other Christians.

“In general, do not use fundamentalist unless a group applies the word to itself.”

Alas, whenever this term is used by the media, you can be assured that it'll have almost nothing in common with its original meaning.

Here's how we got the term: In the early 1900s a conservative movement sprung up within Protestantism -- including the mainstream Protestant churches -- in reaction to liberal theology and the form of Biblical interpretation known as higher criticism. A series of articles was written and collected into a four-volume work called The Fundamentals which was intended to outline the key doctrines, the "fundamentals", of the Christian faith. The movement eventually moved away from its intellectual roots, though, and by the end of World War II it had receded from the culture at large.

Nowadays, though, the term "fundamentalist" has become synonymous with just about any strict conservative stance in any religion or ideology. Once again, it pays to remember that the AP stylebook notes that it has "taken on a pejorative connotations" and advises avoiding it unless a group applies it to themselves.

Unfortunately, that suggestion is rarely followed and the label is applied in seemingly contradictory ways. Take, for example, the title of a report an ABC New's Nightline: 'Modern Polygamy: Arizona Mormon Fundamentalists Seek to Shed Stereotypes.'

The story contrasts a group of "1,500 fundamentalist Mormons" living in Centennial Park, Ariz. with another group of nearby polygamists, "the Fundamentalist Church of Jesus Christ of Latter-Day Saints followers, or FLDS, the group led by self-described prophet Warren Jeffs." There's no indication the Centennial Park polygamists call themselves fundamentalists so why use the term to compare them with a group that does?

The "stereotype" referred to in the title is that Mormon polygamy is repressive to women:

... (The) polygamist community said they are tired of living in secret and want to demonstrate plural marriage as the way they say it should be seen. Hammon said that the stereotype that women in polygamist marriages have no rights, no freedom to leave the community and are only there to have babies is false, as far as he is concerned.

"I can tell you that my door swings both ways," he said. "If they come in, they can go out. I know of no greater freedom for a woman than living in a responsible, caring polygamist home."

Another polygamist explains why he thinks the practice should be decriminalized:

"If I had my choices, I would like to see it done right now. I don't see there is any reason for this lifestyle to be a crime. It's a religion. Not a crime."

And one of the wives adds:

"This is where I choose to be. ... I truly am happy with this lifestyle. I truly would be unhappy in something different, I truly would," Rose said. "Living in a monogamous lifestyle simply would not be full enough for me."

Now imagine if those same lines had not been delivered by Mormons but by members of the Unitarian Universalists for Polyamory Awareness. Would ABC have referred to them as 'fundamentalist' or would they be described as on the bleeding-edge of progressivism?

The problem with the ABC story stems largely from the fact that it's trying to fit the polygamy narrative into the traditional marriage paradigm. But the issue of same-sex marriage has complicated the issue and makes the previously clear lines (e.g., polygamy is an practice of fundamentalist religions) much blurrier.

Nowadays, on the issue of marriage, the Mormon polygamists in Arizona have more in common with the Unitarian polygamists in New York than they do with members of the Mormon church. Why is one group (polygamist Mormons) assumed to be political and religiously regressive while another group with similar views (polygamist Unitarians) are viewed as political and religiously progressive?

That's yet another reason to drop the term fundamentalism: It signifies a sense of unity between disparte groups and creates a fundamental misunderstanding of the complexity of religious affiliations and beliefs.