Invades user privacy to a degree of superfluity. When you add it, you give permission for it to "view and manage your Google Docs documents, display and run third-party web content in prompts and sidebars inside Google applications, allow this application to run when you are not present, connect to an external service, create new documents, view and modify existing documents, and share documents of others." This means ALL documents in your Google Drive. For student accounts, this can be a violation of not only student privacy, but FERPA laws. SAS Writing Reviser can, in essence, create a new document on your Google account, in your name, and share it as you. I will consider increasing the rating when the developer significantly restricts what the app does within user accounts.