This is the best summary I could come up with:

But for thousands of sellers who prefer to ship their own products, starting in October, they will have to pay Amazon “a two percent fee on each sale,” according to internal documents reviewed by Bloomberg.

In February, Search Engine Land reported that higher fulfillment fees and mandatory advertising expenses had increased Amazon’s share of sellers’ revenue to 50 percent.

Bloomberg spoke to several sellers who, speaking anonymously for fear of retaliation, confirmed that they were interpreting the latest fee as “an attempt to pressure them into using Amazon’s logistics services rather than fulfilling orders themselves.”

The letter then detailed Amazon’s past and current conduct allegedly using “unfair methods of competition” to “gain and maintain its market dominance.”

The Justice Department, however, does seem interested in promoting competition specifically in the books industry, last year blocking Penguin Random House from acquiring Simon & Schuster over antitrust concerns.

[Update: The Open Markets Institute’s spokesperson Ashley Woolheater told Ars that the think tank made a similar appeal to the FTC in 2015, which led to meetings with officials but no investigation.

I’m a bot and I’m open source!