Amazon Copyright Laws?

A couple of weeks ago I was going through my spam folder and found an interesting email from a stranger. To my knowledge, I have no idea who this person is or how legitimate this information is but it is causing me a little concern and making me wonder.

I don't want to reprint the information from the email, obviously, without permission but the gist of it is this:

• Through research that she has done while writing another book, and discussions that she has had with various people around the Amazon world, she has discovered that Amazon can and does remove reviews without notice or explanation.

• Amazon retains total and irrevocable ownership of every review that anybody posts on their site.

My standard practice with my own reviews is to write them here on my site, then copy and paste them to Barnes & Noble, Amazon, and Goodreads. I don't necessarily always have time to write a second (or third, etc.) review to post elsewhere.

This concerns me. This will impact how many reviews I can keep up with and the way I write them. Has anyone else heard anything regarding this? Please let me know.