Over on Reddit, there’s a post from a user who has discovered that Amazon’s British branch has a clause in their shipping policies that limits the number of copies a person may purchase.

Amazon.co.uk: most countries in the world. Please note that customers in the US and Canada may be restricted to one copy of certain book titles because multiple copies may infringe US copyright laws.

According to their policy, purchasing too many copies of a single book can be construed as copyright infringement.

At issue is whether or not publishing rights = purchasing rights.

The law presumably exists (I am not a lawyer) to prevent people who live in countries without copyright laws from printing copies of books, however, if you do not have copyright laws in your country, why would you care about them in the first place?  If importing is a problem, I am sure they purchase directly from the publisher and not Amazon.com.