It's no secret that internet users love pornography.  Porn is in fact one of the most searched topics on the internet.  Recent studies have shown that nearly all young men and a significant percentage of young women indulge in porn.  Porn has even invaded smartphones both via browser and apps.

Now a pair of new studies reveal some additional insight into the unique role of porn on the internet.   The first study is from Optenet, a SaaS provider which delivers "on-premise" security. Optenet claims that it found approximately 37 percent of the pages online to contain pornographic content.

The study looked at 4 million URLs.  Among the interesting things it discovered was that porn appears to be on the rise.  Between 2009 and 2010, pornographic sites increased by 17 percent.

The study also offers other interesting conclusions on other types of growing content.  Sites about online games (like World of Warcraft or Final Fantasy XI) have grown 212 percent, sites containing violent content have grown 10.8 percent, terrorism sites have grown 8.5 percent, and illicit drug sites have grown 6.8 percent.

Ana Luisa Rotta, director of child protection projects at Optenet, states, "When you consider that more than one third of the Internet’s content is pornographic, combined with the overwhelming increase in young people now curiously visiting web sites with such ease of access, it is becoming increasingly imperative that adults take responsibility for the management of home PC security."

A second study, led by Professor Gilbert Wondracek, a computer security expert from the International Secure System Lab, looked in to the dangers of pornographic sites.  Unsurprisingly, it found many of the sites harbored malware or engaged in other actions that endangered their users.  Professor Wondracek states, "They have almost inadvertently created a whole ecosystem that's easy to abuse for cyber crime on a large scale."

Researchers spent many long hours first examining the economics of porn.  It found that the majority of sites were free sites that paid sites gave content to, in order to drum up business.  In total, of the 35,000 pornographic domains examined, 90 percent were free.

And apparently some of the free sites weren't trying very hard on security.  Approximately 3.23 percent of them came loaded with adware, spyware, viruses and other software designed to exploit gaping holes on a system's various software programs.  One such hole that some sites are using involves Javascript catchers, which prevent the user from quickly leaving the site.

Other sites redirect users clicking on images that appears to be on the current site to other sites, a risky practice.  Traffic is so essential to the industry, so this business of trading clicks is particularly vital, according to Professor Wondracek.  He states, "Visitors are being abused as click bots.  It's cut-throat competition.  Everybody tries to get as much traffic as possible."

To test whether this could be abused, the researchers created two faux-adult sites, complete with pornographic content.  They then spent $160 USD to get other sites to redirect users to their site.  They then scanned the computers of the 49,000 visitors to the test sites and found that 20,000 were using a computer and browser combination that was vulnerable to at least one known exploit.

Professor Wondracek states, "As an attacker you want to make your life easier.  If you can have these 20,000 people come to a place instantly, why not?  For the average user it might be hard to tell an honest porn site from a dishonest porn site until you click on something"

The researchers suggest using safe browsing modes, found on many browsers.  They presented  the results at the Workshop on the Economics of Information Security held at Harvard earlier this month.