Pirate websites receive 300 billion visitors a year and ebooks represent a small, but growing target for download.

Digimarc and Nielsen conducted a recent study that revealed the surprising statistic that book purates are not kids. 47% of Online users who have illegally downloaded free copies of ebooks are aged between 33 and 44.

Cost is often cited as a motivating factor when justifying theft, and the study reveals the average household income of frequent thieves ranges from $60,000 and $99,000.

Ebook piracy is a global problem. According to the Intellectual Property Office’s latest study of online copyright infringement, 17% of ebooks read online in the UK are pirated – around 4m books.

Dutch firm GfK, found only 10% of all German ebooks on devices were actually paid for, with most of the digital books being pirated.

On average, an e-reader in the Netherlands holds 117 ebooks, with just 11 bought at legitimate websites.

92% of ebook readers in Russia obtained their books illegally.

Ebook piracy is “a very significant issue and of great concern” to publishers, said Stephen Lotinga of the Publishers Association, which works to take down and block pirated ebooks links and sites. “As an industry we’ve not had the situation that the music and film industries have gone through,” Lotinga said. “But that obviously is 4m books that authors and publishers aren’t getting paid for, and should be getting paid for, and it’s a particular worry for publishers at a time when ebook sales are in decline.”