Dropbox will no longer offer unlimited storage on its Advanced plan due to a growing number of users abusing the policy for unacceptable use cases including cryptocurrency mining.

In a blog post, Dropbox explains that it originally decided to offer its Advanced subscription without a cloud storage limit so that businesses "don’t have to worry about scaling storage as their teams grow." However, some users have been seriously abusing the feature.

Dropbox discovered "a growing number of customers" were signing up for Advanced in order to take advantage of the unlimited storage for unacceptable use cases. They include mining cryptocurrency and Chia, reselling the storage to others, and unrelated individuals pooling their storage for personal use.

The extent of this misuse meant that the abusers would "frequently consume thousands of times more storage than our genuine business customers." That can lead to an unreliable service for everyone, so Dropbox decided it's time to switch to a metered model.

Going forward, a Dropbox Advanced plan with three active licenses (costing $24/user/month after a 30-day free trial) will share a maximum of 15 terabytes of storage. Every additional license will unlock a further 5TB of storage.

Dropbox says it will work with the less than 1% of users currently consuming more than 35TB of storage to "make the transition easier." Any Advanced accounts using less than 35TB will be able to keep the amount of storage they are using at no additional cost and will get an extra 5TB of pooled storage for five years.

Last year, Dropbox announced plans to increase the security of its service by implementing end-to-end, zero-knowledge encryption. The company has also been looking beyond cloud storage with new features to attract more customers.