To use drupal views to display civicrm data, you need to grant SELECT on the relevant tables in the civicrm database to the drupal user.
I want to start creating some views because they offer so much more flexibility than civicrm reports, and do not cause the acl_contact_cache deadlocks that are crippling our users' experience. However, the site doubles as a public shop-front and a database of confidential data. By keeping the drupal user away from the civicrm data I felt some confidence that a hacker who exploited some Drupal vulnerability and got access to the database as the Drupal user would not be able to get at the civicrm stuff.
Of course it is not a guarantee, but it's a extra bit of security which I would be eroding by creating the views.
Am I right to be concerned by this? What are the real-life implications? If I choose to go ahead with it, is there something I can do to mitigate the problems it could cause?