[Rob Lister]

I don't think the issue is transferring to another owner, the issue is the necessity of circumventing the DRM to accommodate that transfer. That's where the legal issue comes in.

Form one source: The Digital Millennium Copyright Act of 1998 states that "no person shall circumvent a technological measure that effectively controls access to a work protected under [copyright law]."

And that's exactly what you'd have to do to transfer it unless your license distributor (Amazon, B&N, etc.) otherwise accommodates you.

I know there are previous court cases that upheld this statute. I think there are recent court cases undermine it a bit in certain circumstances (i.e. jailbreaking).

Regardless, the current legal standing is clear: illegal.