"Bigamy has been a crime in Utah for more than 100 years, punishable by up to five years in prison. The new measure would toughen the penalties in the case of underage brides, bringing a polygamous husband or church leader arranging such a marriage up to 15 years in prison.

The House overwhelmingly approved the penalties on Tuesday, and the Senate is expected to take up the bill next week. Gov. Michael O. Leavitt, a Republican and a descendant of polygamists, has "not yet weighed in on the bill," his spokeswoman said.

Despite its unlawful status, polygamy is thriving throughout Utah, practiced by fundamentalist Mormons who shun mixing with the outside world and live by traditions their ancestors brought west in the mid-1800's. The number of people in polygamous families in Utah is estimated at perhaps as many as 50,000.

Separated by their beliefs from the mainstream Church of Jesus Christ of Latter-day Saints, which condemned polygamy as a condition of Utah statehood in 1896, fundamentalist Mormons believe that a woman exists to embody the spirit of her religious teachings and serve her husband, responsibilities that include bearing children as soon as possible. "

From Bowser's linked article [which to be charitable, he was very selective in reading].

And of course, if it gay marriage become legal under federal law, this could open the door for Bigamy to become legal.
Another aspect is what become news.
This only news because law enforcement have acted, and courts are prosecuting the case. Therefore it's visible to the reporters.

For example, what about areas such as in France, where similar cases among fundemental muslims are ignored. And you can take to the bank, that French are ignoring this problem, since they typically ignore more obvious crimes.