Document connected account permissions

Author: davidfischer

docs/connected-accounts.rst

@@ -1,5 +1,5 @@
 Connecting Your Account
------------------------
+=======================
 
 If you are going to import repositories from GitHub, Bitbucket, or GitLab,
 you should connect your Read the Docs account to your repository host first.
@@ -18,3 +18,64 @@ and select `Connected Services <https://readthedocs.org/accounts/social/connecti
 From here, you'll be able to connect to your GitHub, Bitbucket or GitLab
 account. This process will ask you to authorize a connection to Read the Docs,
 that allows us to read information about and clone your repositories.
+
+
+Permissions for connected accounts
+----------------------------------
+
+Read the Docs does **not** ask for write permission to your repositories' code
+and since we only connect to public repositories we don't need special permissions to read them.
+However, we do need permissions for authorizing your account
+so that you can login to Read the Docs with your connected account credentials
+and to setup :doc:`webhooks`
+which allow us to build your documentation on every change to your repository.
+
+
+GitHub
+~~~~~~
+
+Read the Docs requests the following permissions (more precisely, `OAuth scopes`_)
+when connecting your Read the Docs account to GitHub.
+
+.. _OAuth scopes: https://developer.github.com/apps/building-oauth-apps/understanding-scopes-for-oauth-apps/
+
+Read access to your email address (``user:email``)
+    We ask for this so you can create a Read the Docs account and login with your GitHub credentials.
+
+Administering webhooks (``admin:repo_hook``)
+    We ask for this so we can create webhooks on your repositories when you import them into Read the Docs.
+    This allows us to build the docs when you push new commits.
+
+Read access to your organizations (``read:org``)
+    We ask for this so we know which organizations you have access to.
+    This allows you to filter repositories by organization when importing repositories.
+
+Repository status (``repo:status``)
+    Repository statuses allow Read the Docs to report the status
+    (eg. passed, failed, pending) of pull requests to GitHub.
+    This is used for a feature currently in beta testing
+    that builds documentation on each pull request similar to a continuous integration service.
+
+.. note::
+
+    :doc:`Read the Docs for Business </commercial/index>`
+    asks for one additional permission (``repo``) to allow access to private repositories
+    and to allow us to setup SSH keys to clone your private repositories.
+
+Bitbucket
+~~~~~~~~~
+
+For similar reasons to those above for GitHub, we request permissions for:
+
+* Reading your account information including your email address
+* Read access to your team memberships
+* Read access to your repositories
+* Read and write access to webhooks
+
+GitLab
+~~~~~~
+
+Like the others, we request permissions for:
+
+* Reading your account information (``read_user``)
+* API access (``api``) which is needed to create webhooks in GitLab