Religious affiliation: The self-identified association of a person with a religion, denomination or sub-denominational religious group.
I assume that this report was based upon “An extensive new survey by the Pew Forum on Religion & Public Life details statistics on religion in America and explores the shifts taking place in the U.S. religious landscape. Based on interviews with more than 35,000 Americans age 18 and older, the U.S. Religious Landscape Survey finds that religious affiliation in the U.S. is both very diverse and extremely fluid.”
“[Snip] Like the other major groups, people who are unaffiliated with any particular religion (16.1%) also exhibit remarkable internal diversity. Although one-quarter of this group consists of those who describe themselves as either atheist or agnostic (1.6% and 2.4% of the adult population overall, respectively), the majority of the unaffiliated population (12.1% of the adult population overall) is made up of people who simply describe their religion as “nothing in particular.” This group, in turn, is fairly evenly divided between the “secular unaffiliated,” that is, those who say that religion is not important in their lives (6.3% of the adult population), and the “religious unaffiliated,” that is, those who say that religion is either somewhat important or very important in their lives (5.8% of the overall adult population).” Statistics on Religion in America
Allen Downey, a computer scientist at the Olin College of Engineering in Massachusetts correlates the increase of Internet use with the increase of the religious unaffiliated, because while in 1990, eight per cent of Americans had no religious affiliation. In 2010, that figure stands at 18 per cent, or 25 million people. At the same time the number of people who used the Internet per 100 of population when from near zero in 1990 to about 75 per 100 today. Yep, it correlates alright. Article
I count myself among the religious unaffiliation in that I do not belong to a church, and do not hold to a particular doctrine, but I do consider myself a Christian. My unaffiliation has nothing to do with my Internet use. A correlation like this is useless, and cannot prove causation. You could also correlate the increase of electric car in use in this time span with the increase in the unaffiliated, but the fact that they increased together means nothing. One could just as easily claim that the increase in the increase in the unaffiliated caused the increase in Internet use instead of visa versa.