Earlier this month, Microsoft updated the Universal Online Services License Terms to clarify that it now prohibits cryptocurrency mining unless you have prior permission. According to The Register, which spotted the change, Microsoft updated the contract to help protect all customers using its cloud.

The company recommends obtaining written permission to obtain permission to mine using Microsoft cloud solutions. He did not specify where his request should be directed, however, and said he might consider mining for testing and research purposes to explore security.

The change was reportedly made because mining could cause crashes and break Microsoft’s online services. The company also stated that crypto miners “can often be associated with cyber fraud and abuse, such as unauthorized access and use of customer resources.”

Microsoft is not the first company to limit mining in its cloud network. Oracle and OVH generally do not allow mining on their networks, Digital Ocean and Google Cloud require written permission, and Amazon Web Services restricts activity in their free tier. It’s unclear how many cryptocurrency miners will be impacted by this change, but due to Bitcoin’s relatively low price, mining has become a more difficult task economically.