Home taping is killing music. This slogan adorned record sleeves when the music industry thought the audio cassette was going to crash market.

Of course, home taping did nothing of the sort.

Since then, computers have made it easier than ever to make perfect copies of digital media.

We have been able to "clone" audio CDs for several years and now the tumbling price of recordable DVD drives and the emergence of new software has meant it's the movie industry's turn to get shaky.

Some of the applications in this feature are capable of getting round the copy protection measures DVD manufacturers have put in place to prevent people copying their favourite films.

You can then copy the movie to your hard disk, a blank DVD or even a CD. We'll examine just how these programs work and also take a look at the legal implications of using such software.

Unfortunately, if DVD copying sounds almost too good to be true, that's probably because it is. It is illegal under British copyright law to copy or "rip" DVDs.

It is, however, equally illegal to make a tape of your favourite album to play in the car or photocopy a page from a book - and you don't see the courts filled with people accused of that.

Here's what our legal expert from law firm DMA Legal had to say on the subject: "It is prohibited to make a copy of a DVD or CD for private use.

"Under the Copyright, Designs and Patents Act 1988, there are no specific private use exceptions. However, as an example, the following activities do not infringe copyright.

"Fair dealing with literary, dramatic, musical or artistic works for the purposes of private study.

"A recording of a broadcast for private and domestic use for the purpose of enabling it to be viewed/listened to at a more convenient time and making a back-up of a copy of software where the individual is a lawful user."

While it's technically illegal, it is also highly unlikely EMI will sue you for transferring MP3s of your own Beatles Greatest Hits CD to your Apple iPod, though.

The same sort of argument works for DVDs, which is why the products we're looking at tend to market themselves as DVD back-up programs.

But although there is plenty of hardware and software allowing us to copy copyrighted materials, we could still technically be breaking the law, even if it is for personal use.

Computeractive covered copyright laws in detail back in issue 132 so read that to see where you stand.

Given the recent slump in CD sales, the movie industry is understandably worried about DVD-copying software.

Such software could, theoretically, make it possible for a crook to make cheap copies of movies such as Harry Potter and the Philosopher's Stone and then flog them.

More likely instances of illegal domestic use could involve renting a disc from your video library and making a copy of it to keep before returning it to the shop.

Similarly, borrowing a movie from a friend and copying it would be seen as a "lost sale" by DVD manufacturers and could also mean you've broken the law.

There are less obvious ways in which you could be in trouble for using DVD copying software.

Some software copies from DVD to DVD or CD but others allow you to extract the audio and video data to a file on your computer's hard disk.

In truth, it can take days to download a feature film from such a service.

Here's what a representative from the British Video Authority had to say on the matter: "Some factors limiting film downloading will exert less influence. Notably, the time taken to download.

"These influences are relative to the distribution of broadband and recordable DVD players. But it is already affecting purchase behaviour."

Many people believe the copyright laws are behind the times. In its mission statement, 321 Studios, which manufactures DVD X Copy, believes "consumers who copy DVDs for their personal use are exercising their right of fair use - an exception to copyright law upheld by the US Supreme Court to avoid an irreconcilable conflict between copyright law and the First Amendment's guarantee of free speech".

Copyright laws in the USA differ from our own but the product is available for purchase in the UK nonetheless.

DVD X Copy allows users to make almost perfect, high-quality copies of DVD movies. It can get around copy-protection software and even retain menus, and trailers.

However, 321 Studios also makes it clear it is against piracy.

The application electronically embeds a public disclaimer into the copied DVD, uses an electronic watermark that can trace piracy back to the point of purchase.

So why would you want to make a back-up copy of your own DVD? 321 Studios suggests discs can get scratched by heat.

Indeed, at £20 a pop, you'd probably be pretty peeved if a DVD movie suddenly stopped working. While discs aren't as indestructible as we once thought, DVDs are resilient.

Copying DVDs is not the most time-efficient practice. It's a very slow process.

There are plenty of other shareware DVD rippers and copiers available on the web but these occupy an even more legally questionable area.

The four main legal contenders are 321 Studios DVD X Copy, BVRP DivX Video Duplicator, E-promocard Movie Jack 2 and Pinnacle InstantCopy.

DVD recording in general is still in its infancy and movie-copying software, in particular, is at an early stage.

Whether such programs develop is down to the law.

This article is adapted from Computeractive 138, which contains reviews of the four programs mentioned.