This is an interesting question because one of the legitimate uses of peer-to-peer torrent networks like Limewire is to disseminate very large files efficiently. One of the premier uses? Linux operating system distributions, which can be hundreds of megabytes up to even gigabytes in size.

There are other legit uses too, including filmmakers who make their movies available directly, musicians dropping music files onto peer-to-peer networks to try and gain interest and enthusiasm in the marketplace, and even political and (dare I say it?) rather wacko ebook screeds that seek legitimacy by greater dissemination through populist networks.

On the other hand, there are also zillions of illegal files out there, surreptitiously videotaped cinematic movies, ripped commercial music CDs and DVDs, software that you should be buying, not downloading free, and on and on.

A quick visit to somewhere like Mininova.org will demonstrate just how much is out in the peer to peer networks, and how it's really almost all illegally copied and disseminated content.

Is it fair that this content is distributed freely for anyone who wants to connect and download it? Well, that's not really the issue, is it? The fact is that copyright law does protect the creators of this intellectual property and it does mean that copies that are not authorized by the copyright holder are indeed illegal.

Which brings us back to the essential question of how you can tell when you see something show up in your Limewire search results window. The answer isn't black and white. I would say, however, that you can be safe in knowing that if you don't know for sure that it is a legal file, that your assumption should always be that it is illegal and you shouldn't touch it. I think you'll know, frankly. If you see something like "Microsoft Office" or "Shrek 3" on the list, well, there's no way that Microsoft is going to be distributing free copies of its software, nor is Dreamworks going to have authorized free digital copies of a movie that cost it millions to produce.

Be thoughtful with what you download, and good luck to you.

This article was written by contributing editor Eric Savage.