Epic Games has filed a motion for a preliminary injunction to stop Google from removing independent music storefront Bandcamp from the Android app store — which Google has apparently threatened to do because Bandcamp is using its own billing system instead of paying Google an app store fee.

Bandcamp, which Epic acquired in March, has used its own billing system on Android since 2015, and was able to do so because of rules exempting digital music from having to use Google’s billing system, according to a blog post from Bandcamp co-founder and CEO Ethan Diamond. “However, Google is now modifying its rules to require Bandcamp (and other apps like it) to exclusively use Google Play Billing for payments for digital goods and services, and pay a revenue share to Google,” Diamond says.

Under Google’s new rules, Bandcamp would have to make changes beginning June 1st. Diamond says Bandcamp would be forced to choose between passing on fees to customers, passing on fees to artists, running its Android business at a loss, or turning off digital sales in the Android app.

Epic argues that the switch to Google’s billing system would affect its ability to continue giving artists 82 percent of their Bandcamp revenues, because it would have to pay Google 10 percent — yes, 10 percent, not 30 percent, since it seems Google offered Bandcamp some sort of sweetheart deal here. “Paying Google even a 10 percent revenue share would force Epic to change Bandcamp’s current business model or else operate the Bandcamp business at a long-term loss,” argues Epic.

Epic also claims music artists might have to wait longer for their money, too, saying that its current payment system allows artists to be paid within 24 to 48 hours of a sale, but that Google doesn’t pay developers until “15 to 45 days after a sale.”

While that argument certainly sounds compelling, it didn’t work when another platform that tries to pay creators, Fanhouse, tried it against Apple last year. Fanhouse wound up adding a 50 percent surcharge to cover the Apple tax. That could be why Epic is going to the courts rather than simply trying to publicly shame Google — but it could also be that Epic hopes to use Bandcamp as a pawn in its larger fight against Google and Apple. Epic sued both Apple and Google in August 2020, alleging antitrust violations after both platforms kicked Fortnite off their stores when Epic introduced its own in-app payment mechanism to the game. The Google case won’t go to trial until 2023.

In today’s filing, Epic says Google is changing its policies “under the guise of a ‘clarification’ that it announced in September 2020.” But that update hasn’t just affected Epic — earlier this month, Barnes & Noble removed the ability to buy digital books from its Android app, while Audible no longer lets you use a debit or credit card to buy Audible titles, seemingly to avoid paying Google’s fee. And in this case, Google appears to have offered Bandcamp a discount at 10 percent rather than 30.

Epic also notes that building infrastructure to integrate Google’s billing system would “require significant time and effort” — right now, Bandcamp’s in-app solution is “fully integrated with PayPal.” But again, as Epic admits, Google announced these changes well over a year ago, and before Epic bought Bandcamp. It seems likely Epic knew about the upcoming billing changes when it purchased the company.

And it wouldn’t be out of character for Epic to lay the groundwork for a legal trap well in advance. Epic’s own internal emails show that it laid such a trap in the Fortnite case: “[T]he goal is draw Google into a legal battle over anti-trust,” wrote Epic marketing director Haseeb Mailk in a September 2019 email. “If we are rejected for only offering Epic’s payment solution. The battle begins. It’s going to be fun!”

You can read two such emails here — look for items #35 and #38. And you can read the full motion embedded below.

Update April 29th, 10AM ET: Updated to clarify that Diamond proposed pulling digital sales, specifically, from the Bandcamp app.