This headline is not wholly accurate. The relevant sentence is at the bottom of the first page:

"At the 2003 meeting of the American Academy of Matrimonial Lawyers, two-thirds of the 350 divorce lawyers who attended said the Internet played a significant role in divorces in the past year, with excessive interest in online porn contributing to more than half of such cases. "

So two-thirds of divorce lawyers say the Internet played a role, but porn was involved in "more than half" of those. The article is silent on how much more than half.