All you can eat ebooks makes even more sense than all you can eat music. There has got to be an upper limit on the amount of books a person can read and therefore buy, most people will read fewer than that. There has got to be a good business model offering unlimited ebooks for a monthly subscription. This whole per unit cost fopr digital media has never made any sense to me, there are no marginal costs so why not work out a subscription price point where you make more money than selling "units" and offer unlimited downloads. Content producers make more money, consumers get unlimited access, everybody wins.
I used to work for a company that made HR software. We had a pretty similar situation to the one described. A number of years previously the current shareholder bought out his partner to become the sole shareholder (it is a private company). The outgoing partner retained no rights to any of the company's products. A number of year later we discovered that another company was selling a product that bore a striking resemblance to one of our older generation products. We were not actively marketing this product any more but it was still available and we were supporting a number of customers who still used the software. We contacted the other company and sure enough they told us that they had purchased the source code for it from the former business partner. We sent them a copy of our source code for comparison and they said that the it was a very close match source code they had been sold. We could have taken the easy route and sued the company for selling our product. However they were clearly the victims here so what we did instead was that we sold them the rights to the source code (it was after all and old generation product), and then worked with them so that they could now sue the outgoing business partner for selling them source code fraudulently.
This seems to be a good common sense way of dealing with this sort of thing, the victims cooperate to go after the perpatrator.
There is almost no Fair Use rights here in the UK, you cannot copy anything ever unless you have a specific license to do so. The PPL (the UK organisation reponsible for public performance and broadcast licensing of the sound recordings owned by most UK record labels), are trying to get digital (i.e. MP3) DJs to buy their "Digital DJ License". For you £200($350ish) a year you don't get any public performance or broadcasting rights, you do not get the right to download anything or rip anyone elses CDs. All you get is a license to rip to your hard drive, CDs and vinyl you already own, and for personal use only. In the USA this would be covered by standard fair use rights, but we have no such thing in the UK.