The weekend papers brought some interesting news about the world of e-books. One article, in the Guardian, reported that 'super agent' Andrew Wylie has moved into direct digital publishing of his authors – only to have his new venture Odyssey Editions denounced by Random House and Macmillan. Odyssey will sell digital editions of modern classics for the Kindle. Random House sent a legal letter to Amazon and cut off business with the Wylie Agency. It reckons it has the rights to the digital property.

Meanwhile, the Financial Times the same day reported on agreements between some publishers, including Bloomsbury, and UK libraries. For a fee of 0.1 pence per head of population, a library can offer its customers free access to e-books published under Bloomsbury's Public Library Online project, which has several publishers now signed up. Similar library subscriptions are already in place for some reference books including the Oxford English Dictionary Online. However, other UK publishers have sent off a letter of complaint to the Department of Media, Culture and Sport. (I love the trans-Atlantic difference – we send for our bureaucrats, the Americans for their lawyers.)

As a former competition regulator, I find it hard to feel sympathy with the mega-merged titans of the publishing world, no matter how much they are shocked – shocked! – by the prospect of new, technology-enabled entry into their business. I hope the DoJ is reading the letter to Amazon carefully. OK, neither Amazon nor even the Wylie Agency lacks market power of their own. But the sad reality for powerful incumbents is that the technology of e-books and digital reading devices will and should cut their profits. That's how new technologies benefit customers – more choice and lower prices.

However, the technology also raises some fascinating questions about what constitutes property. What is it that you buy when you buy a book? Libraries, sharing, and second hand book shops have long undermined the purity of the principle that the originating publisher has absolute control over the number of people entitled to read the words in a book. But before digital readers, the friction of physically moving the book from one reader to another was enough to limit the danger of large-scale loss of control. Now the question of what property is it, exactly, that's being traded is at the foreground. There will be the same mania over DRM and copyright-protection as there has been with music, and no doubt big publishers will make the same arguments as big music companies.

But the truth is that intellectual property isn't the same as physical property. Property is a more mysterious notion than we believe, and is maintained by social conventions. James Boyle sets this out brilliantly in his book The Public Domain. When I buy a drink in a pub, the convention is that I've bought the liquid contents but not the glass – unless it comes in a plastic beaker, in which case I've bought that too. These rules aren't set out above the bar but maintained by custom and practice. So when I buy a book, am I buying the physical book, and is it therefore like buying a coat, which I can freely sell on or give away later? Or am I buying the words and ideas for a rental period, with no rights to pass them on? It's always been the former, but publishers would now like to claim it's the latter.

My money is on the ideas breaking free in the end, but there's bound to be a lot of work for lawyers first.