Last week, Barnes & Noble's Nook e-book reader took on Amazon's Kindle, joining the Sony Reader and several smaller players. And that arena has only just begun to heat up; in the next few months, a raft of additional models will appear.

One of my readers is alarmed by a precedent being set:

"When the iPod introduced music lovers to the idea of copy protection, a years-long war ensued between consumers and the RIAA (and others). The primary issue was that if I purchased a song for my music player, it would only play on that player; I didn't really own it, per se. Years later, we finally have digital music without copy protection.

"Enter the Kindle and the Nook and copy-protected books. If I purchased a Kindle a year ago, and I have 30 books for it, and now want a Nook... you can guess where this is going.

"Where are the upset people? I never see reports on how e-book copy protection is bad for consumers. Didn't we learn anything from the music industry? Does this lock-in bother you? Am I missing something?"