MetaCert aims to block porn throughout the home (podcast)

There are lots of tools out there to help parents keep their kids away from what's typically considered inappropriate online content. Most, however, run on PCs and Macs, which means all bets are off if, for instance, a child surfs via a smartphone or a tablet.

MetaCert has a different idea. It's now beta-testing a server-based porn filter parents can set up to automatically block access to pornographic sites across their entire home network. It does so by hosting the filter on a DNS, or domain-name system, server -- effectively pushing the filter from individual computers into the cloud.

MetaCert isn't the only service using the DNS approach. According to CEO Paul Walsh, though, the company is working on software that will enable parents to easily switch between their filtered DNS and a non-filtered DNS without having to deal with sometimes complicated operating system or browsing settings.

The San Francisco-based company has crawlers that constantly look for pornographic content. They claim to have labeled more than 627 million Web pages.

I wasn't able to test all of MetaCert's assertions, nor did I compare it to other approaches to filtering. But MetaCert is noteworthy in terms of the sheer number of pages it claims to block and its use of crawling software and focused algorithms that aim to keep its database up-to-date.

Walsh said that many porn sites have links to other sites -- often operated by the same people -- so that if a site has a link from a known porn site, it probably also contains porn. However, to make it on the list, it has to have some specific attributes, and if there is any doubt, it's evaluated by staff. Still, there are cases where the software has accidentally blocked sites and if someone finds a site that's been inappropriately blocked, they can report it to the company, which will remove it from the blocked list if it turns out not to be porn.

Although I wasn't able to verify this independently, Walsh said that the company's approach yields very few false positives -- i.e., cases in which a filter inappropriately blocks a non-porn site as porn. (Sites about breast cancer or the safe use of condoms are frequent false-positive victims.)

Walsh sent me an email exchange between his staff and the editor of a gay-news service who complained that his site was incorrectly blocked even though it had no porn. MetaCert told the editor "Unfortunately your website was referenced from a site which had been flagged as XXX and also contained keyword hits which resulted in it being incorrectly categorized as pornographic." The company then unblocked the site. Walsh claims that their MetaCert's error rate is less than 0.3%.

MetaCert only blocks pornography, not sites with violence, drugs or other potentially inappropriate material. "Different people in different countries have a different opinion as to what's appropriate or inappropriate for their children when it comes to subject matter such as violence, gambling, [and] general nudity," Walsh said in a recorded interview (scroll down to listen). "We're focused on the one type of content that 99.9 percent of all parents want to block for their children which is pornography or sexually explicit content."

Products for networks, browsers and iPads
The company offers several more traditional products, including extensions for Chrome and Firefox that block objectionable material. It's also about to release an iOS browser for the iPad. Although Apple doesn't currently offer any filtering of its own, it does allow parents to password protect access to Safari, so it's possible to install MetaCert's browser -- called Olly -- and restrict access to Safari. Parents can still access Safari with the password.

If someone using MetaCert's DNS server tries to access a blocked site, they will be redirected to a page telling them it's blocked content. If the router is configured with the DNS, all devices on the network -- including game consoles, tablets, media players and smart phones connected via WiFi will be protected.

The MetaCert DNS server can't filter sites on devices that access the Internet via cellular or alternative WiFi hotspots, but its Olly iOS browser can still block them.

About half of U.S. parents use parental controls
A 2011 survey commissioned by the Family Online Safety Institute found that 53 percent of parents use some type of tool to monitor or control their child's online behavior. As I pointed out in this post, filters have their place, especially for protecting young children from accidentally stumbling on disturbing content, but they're not a panacea, are not appropriate for all families and all children and should never be used as a substitute to parental involvement.

Click the link below to listen to Larry's interview with Metacert CEO Paul Walsh.

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