After China imposed a record antitrust fine on Alibaba Group Holding Ltd., the e-commerce giant did an unusual thing: It thanked regulators.

"Alibaba would not have achieved our growth without sound government regulation and service, and the critical oversight, tolerance and support from all of our constituencies have been crucial to our development,” the company wrote in an open letter. "For this, we are full of gratitude and respect.”

It’s a sign of how odd China’s crackdown on the power of big tech has been compared with the rest of the world. It's unlikely Mark Zuckerberg and Tim Cook would express such public gratitude if the U.S. government were to hit Facebook Inc. or Apple Inc. with record antitrust fines.