Supress exportation of PII data

Environment: CRM 2015 Cloud

We want our users to be able to see PII data on the contact entity while they are using the CRM UI but we do not want them to export or pull this data using the API.  I can't use field level security because I want the users to be able to read this data while in CRM.  We still want to grant export rights to some users.

Thanks

Scott Clancy