China’s crackdown on the crypto industry is targeting mining companies that have tried to masquerade as research centers and storage facilities to keep their businesses going, according to people familiar with the matter.

Inspections escalated this month in several Chinese provinces, targeting illegal mining activities in colleges, research institutions and data centers, said the people, who requested anonymity, citing concerns about the country’s energy supply in the upcoming winter season as one of the reasons for the intensification of the search.

A new round of scrutiny could reduce the amount of cryptocurrency mining from China, after years of control. As recently as April, the mining operation had 46% of the global margin rate, a measure of the computing power used in mining and processing, according to the Cambridge Bitcoin Index for electricity consumption.