CARY – Tim Sweeney, the billionaire owner of Epic Games who is dueling tech giants Apple and Google over what he considers antitrust issues, took to Twitter over the weekend to talk up his case. The comments came after Tesla and SpaceX CEO Elon Musk tweeted his support for Epic’s ongoing legal battles.

“The Apple Tax is far more pernicious than many realize,” Sweeney warned in a tweet Friday from his personal account.

‘“It only applies to digital goods accessible on iOS”, they say — but in the future all physical goods will have a digital presence, and Apple will tax and gatekeep world commerce. Apple must be stopped.”

Elon Musk tweet backing Epic Games in suit vs. Apple triggers global response

Epic sued after Apple banned Epic’s big hit Fortnite, Apple countersued and a decision in the suit is due from a federal court in California. Epic also is fighting Apple in Australia and Europe. It recently amended a complaint against Google.

Sweeney expanded his Apple warnings in two later tweets:

“The foundations of the technology world were built by makers, not takers. The Internet, the Mach kernel, the Linux kernel, the web. The other guys showed up later and used them to build paywalls around other peoples’ work. Their day of reckoning is coming,” he wrote.

Linux is the open source foundation for Raleigh-based Red Hat.

The Mach kernal is defined this way by Wikipedia: “Mach is a kernel developed at Carnegie Mellon University by Richard Rashid and Avie Tevanian and derived originally from 4.3BSD to support operating system research, primarily distributed and parallel computing. Mach is often mentioned as one of the earliest examples of a microkernel.”

Sweeney also questioned Apple’s 30% fees fir in-store sales. Google charges 30% as well.

“Another way to think about 30% store fees is: Unless a business has an unheard-of 60% gross profit margin, the store monopolist is earning more profit than the creator,” he tweeted. “And if the business has less than a 30% gross profit margin, then it’s put out of business entirely!”