The Small Publishers Association of North America (SPAN) take up the cudgels:

Amazon/BookSurge Antitrust Lawsuit Campaign
The Campaign

Recently, the SPAN Board voted to support the class action antitrust lawsuit, BookLocker.com, Inc. vs. Amazon.com, Inc.
In late March, the news broke that Amazon had begun a new policy requiring print on demand (POD) publishers using Amazon’s distribution services to print their books using Amazon’s subsidiary BookSurge.

Link to the full story here.