With electronic books growing in popularity, the publishing world focuses on fighting the threat of digital book pirates, much as the music industry once did with illegal downloading. Publishing experts from the United States and Britain attending the world's biggest book fair here say ebook theft is unlikely to go away, but is a manageable problem with vigilance and action already underway. Ebook readers -- devices such as the Kindle by Amazon and Apple's iPad -- are fuelling demand for digital books, which account in the US for about 20 percent of book sales, Claire Holloway, of publishing services provider Bookmasters said. "If you give normal, regular, upstanding citizens a legitimate route to your material they are most likely to attain it legitimately, most people do not want to steal," she said. However, failing to offer a legitimate digital version of a book plays into the hands of pirates, who often simply distribute a scanned version of the book on the Internet, said the Ohio-based operations manager. Academic and text books tend to be illegally copied more than fiction due to their high prices and the fact that students often only need them for a term prompting student pirating networks, she added. According to the German Booksellers' and Publishers' Association, some 60 percent of electronic books in Germany, where the market share is still under one percent, are being downloaded illegally. But Richard Mollet, chief executive of The Publishers Association, said it was difficult to calculate the size of the problem in Britain, where about four percent of combined print and ebook revenues come from digital works. "It's a very hard thing to do a study of because you have to ask consumers 'those ebooks that you downloaded illegally, how many of them are actual direct substitutes for sales'?", he said. Unlike in music where illegal services developed faster than legal ones for downloads, he said ebook retailers were used to dealing with publishers so "the ecosystem that built up around digital was legal". "We are in a happier place than music was in this stage of its digital evolution," he said. However, he warned against complacency. People will always try to get pirated ebook content either because they believe it should be free, simply because they can, or because they do not want a corporate account or are underage, he said. "All these factors mean infringement will be present in our market, but it's likely to remain a manageable proportion," he added. One of the steps The Publishers Association has taken is to set up an online service that allows members to identify where their content is on an infringing Internet site anywhere in the world. A legal notice is sent, which in 86 percent of cases results in the offending site agreeing to remove the content, Mollet said. For Thomas Mosch, of the Federation of German Technological Companies, it is a question of finding a balance and not scaring off well-meaning people willing to pay for legal content with over-rigorous measures. "You will never be able to do anything about 10 to 20 percent of piracy," he said. "But with 80 to 90 percent of people ready to pay, the publishing industry should be able to live."