The Good Without the Bad and Ugly
Allowing your children unfettered Internet access to your computer can be like letting them run loose in Times Square at night. If you've ever mistakenly typed the wrong URL when using a browser, you are apt to have come across some objectionable content--the logic goes, if it happened to you, it will probably happen to your kids. You can reduce the likelihood that this will happen by installing a content-filtering application on your Macintosh. Two of the best content-filtering applications are SurfControl's Cyber Patrol ($49.95; www.surfcontrol.com) and Intego's ContentBarrier ($39.95; www.intego.com).
Cyber Patrol is a ratings-based approach to content filtering. When you install the software, you specify the types of content you want to filter. Content can range from sexual or pornographic material to violent or illegal topics. You can specify filters on a user-by-user basis and pick any combination of topics to limit. When a user tries to go to a Web site, the Web address is compared with a list maintained by SurfControl. If the site is allowed, you can see it--if not, you are presented with a message saying that the content is not permitted. You can limit other Internet use as well, such as news, e-mail, and messaging. If you are interested in limiting Internet access time or limiting access at certain times of day, Cyber Patrol will also let you add these filters. The CyberNot list is updated automatically when you subscribe to the service so your filters can track the ever-changing content on the Internet.
Intego's ContentBarrier follows a similar approach and many will appreciate its cleaner user interface (Figure 1). It supports multiple users, lets you regulate the times that Internet access is allowed, and can prevent the user from supplying personal information to those with whom you might be unwilling to share it.
Figure 1 ContentBarrier lets you set up filters for all the folks who use your Mac.
These approaches to content filtering are by no means foolproof. The SurfControl approach in particular relies upon the CyberNot Oversight Committee to categorize sites with potentially objectionable material. With new sites appearing all the time, it is hard for the committee to stay ahead of some sites that may contain material you would rather your child not view. There is no substitute for supervised browsing to prevent the presentation of unwanted content.
Sharing with Your Peers
Remember the Napster phenomenon that took place during 2000 and 2001? This system, based on a peer-to-peer file-sharing model, enabled users to share files, in this case digital music, with the world. Napster's approach was not entirely peer-to-peer since it depended on directory servers that tracked content and the sites on which it was stored. In case you missed it, a massive copyright storm erupted and Napster shut down its service with the hope of reinventing itself.
Concurrent with the ascension of Napster, other true peer-to-peer file-sharing systems began to emerge. Unlike Napster, which was focused solely on music, these others demonstrated that anything could be shared--images, music, video, applications, and documents. One of the more popular is Gnutella, an open, decentralized, peer-to-peer search system that is used to find and share files. Gnutella is not an application, it is a protocol for sharing information on a peer-to-peer basis. Client applications, of which there are many, reach out to other Gnutella systems, telling them what they have when queries are sent over the Internet. (This is a simplification of the process--you can find more information at http://gnutella.wego.com/.)
There are a few Gnutella client/server applications for the Macintosh. LimeWire (www.limewire.com) and Mactella (www.cxc.com) are two popular freeware examples (Figure 2). They're both available for both Mac OS 9 and Mac OS X. The beauty of Gnutella is that it allows you to share virtually anything.
Figure 2 With the LimeWire client you can access Gnutella, one of the most popular systems for peer-to-peer file sharing.
It would be irresponsible to recommend freely sharing copyrighted content with the world: It is illegal to post and download content without the assent of the copyright holder. You can generally restrict access and limit what you share by tweaking the application's settings.