At the moment, we know that you can mask data whilst seeding it into an environment. However, what we would like a way to mask data that already exists in an environment.

A use case is that we have a full sandbox that contains customer data that we want to mask without needing to seed the data in first.

It's a common use case for organisations that deal with 3rd party suppliers but do not want their customer data exposed to the 3rd parties. For instance, a Salesforce implementation partner is delivering a project. They need access to the environments to build and deploy but they don't need to see the customer data, which should be protected. The data already exists in partial or full sandbox so an admin just needs to mask personal identifiable data without needing to delete all the data to seed back into the environment