And it appears legal threats on the issue are being used by large publishing companies in attempts to silence their smaller rivals.
Late last month, the owners of LetsRun.com, a small site for running enthusiasts, received a letter from the lawyers of its biggest rival, Runner's World.
Brothers Robert and Weldon Johnson, owners of LetsRun.com, initially thought the letter - which claimed that they had infringed copyright by linking to an interview page inside the Runner's World site - was a joke.
They claimed they had linked to the article itself, an interview with 800-metre Olympic champion Peter Snell, because the runnersworld.com archiving system was unreliable. They also claimed the bigger site was targeting them because LetsRun.com editorial had criticised its rival in recent issues.
Last week runnersworld.com editor Amby Burfoot ended the controversy by admitting the problem was caused by his lack of web savvy; he did not realise the brothers were linking to printer-friendly pages.
But Robert Johnson complained that other sites had deep-linked to articles on runnersworld.com without receiving threats.
According to Brian Morrissey of internetnews.com: "What might be an interesting David versus Goliath story in the close-knit running community could turn out to be a harbinger of more legal cases where publishers seek to control their content by targeting deep links.
"Until recently, the issue of deep linking seemed to belong to the internet's early days. After all, links are what makes the internet so unique. In what was thought to be the seminal case over deep linking, Tickets.com rebuffed a challenge from Ticketmaster over its practice of linking to pages deep in the Ticketmaster site. The judge in the case ruled that deep links do not violate copyright law, so long as it is clear who is responsible for the material. The judge compared hyperlinks to a card index at a library."
But last month a small news site called BarkingDogs.org received a 'cease and desist' letter from lawyers representing Belo Corp, owner of the Dallas Morning News.
Site owner Avi Adelman said: "It was the dumbest thing I'd ever heard - the first thing you learn about the net is how to link from here to there."
The legal letter claimed Mr Adelman was infringing Belo's copyright by allowing his readers to bypass dallasnews.com's registration system, located on the homepage.
Paul Levy, a lawyer with Public Citizen, an advocacy group that is giving Adelman legal advice, wrote back claiming the notion "was without merit, if not preposterous".
Mr Levy said it appeared that the legal action was 'targeted', because no other sites received similar letters. "It's certainly a way of suppressing the free speech of inconvenient speakers," he added.
Mr Levy has not received a reply to his letter, and Mr Adelman has heard nothing more from Belo.
The Danish Newspaper Association (DNPO), which represents the country's biggest broadsheets, is also engaged in a court battle to stop smaller news sites linking to its stories. Its main target is newsbooster.com.
However, the judge presiding over the case has already told the DNPO to "go away and revise its reasons for taking legal action". The case is due to continue on 24 June (2002).
A Newsbooster spokesman said: "We believe we are giving those papers some free publicity by linking to their sites."
But while Denmark's big players look unlikely to win this case, they are already following another plan to eradicate their web competition.
Politiken, Berlingske and Jyllands-Posten - former rivals for the print market - have decided to co-operate and form a common online news database. If the Danish Competition Authority endorses the service, it is expected to fast become the most dominant player on the market. Its database will hold archives of all the country's major newspapers and magazines.
Writing for europemedia.net, Farid Fellah said: "This suggests that the Danish newspaper industry has joined up to stay alive in the future. Should the industry achieve a ban on deep links and establish a common media database, it will not leave much room for competitors."
Meanwhile, a new US-based service is providing free advice to web site owners who receive 'cease and desist' threats. The Chilling Effects Clearinghouse is a joint project between the Electronic Frontier Foundation and Harvard, Stanford, Berkeley, and the University of San Francisco law school clinics.
The site says: 'We are excited about the new opportunities the internet offers individuals to express their views, parody politicians, celebrate their favorite movie stars, or criticise businesses. But we've noticed that not everyone feels the same way. Anecdotal evidence suggests that some individuals and corporations are using intellectual property and other laws to silence other online users.'