When I told my grandmother a few years ago about my fascination with this newfangled computer network called the Internet, she had a discouraging question: "Isn't that just for watching pornography?"

Now I can safely answer her: "Only sometimes."

That's because a study by Internet research firm Hitwise found that Web traffic in the U.K. to social networks has overtaken adult websites.

The same phenomenon occurred in the U.S. in the middle of 2007, but social and sexual sites continue to battle it out, frequently overtaking one another on a monthly basis. Will the same be true of the Brits, whose porn use took a back seat to social media last October and continued that trend for the rest of the year?

The study comes after an array of news reports about the porn industry's vulnerability to the slumping economy. This seems to be another fork in its side. But then again, social media aren't immune either--just look at the various Web start-ups, including Digg and Flickr, that recently announced job cuts.

The Hitwise report gives some interesting statistics on website demographics. For example, the majority of adult website frequenters are male.

Wait, that's nothing new. But on the flip side, almost 55% of social-media and forum users are female.

Could the trend stem from more women taking to the Net and gravitating to the social networks rather than the male-dominated, seedy underbelly? Just something to Twitter about.

-- Mark Milian

Chart by Hitwise