From Gordon Ramel
In your article on Amazon’s plan to enable the sale of second-hand MP3s and ebooks (23 February, p 22) you state that US company ReDigi is selling second-hand e-music, and that “software checks the seller does not retain a copy”.
I understand how it can check for copies in online and cloud-based storage, or even a hard drive and devices linked to the seller’s computer, but what about a spare laptop or digital Walkman?
Huai'an City, Jiangsu Province, China
