B&N did something shady, sure, but in very plain language told you what they'd done, how to be removed, and during the process suggested why it would be worthwhile to be on their list. Their transparency is respectable.
Organizations share gtheir mailing lists ALL THE TIME. If I pay a membership to museum for a year, I suddenly have five similar museums sending me their marketing info in the mail.
I used to work at a non-profit where this happened constantly. Sure, it wasn't a lot of data about what I have done, but it was basic demographic stuff. To me it made no sense, you'd think that you'd want to protect your donation base at all costs, but this is how deals/partnerships are made between organizations.
Who knows what Facebook is doing with all of that data. If only they were as transparent as B&N with it.
http://www.barnesandnoble.com/container/stores.asp?PID=39742
I think that they've done a fine job with disclosure and much better than many companies have done.
They are now giving you a very visual notice that you can opt out.
