Yesterday Google announced that Google Drive will soon set expiration dates for document access. They even give a scenario:
“For instance, imagine your business hires an outside contractor for a project lasting three months. To complete the job, that contractor needs to view a spreadsheet containing the contact information of your employees. Following this launch, you’ll be able to share your employee list in Sheets with the contractor, give them view access only, and set that access to expire when their contract does (in three months). If the contractor attempts to open the spreadsheet after the expiration date has passed, they’ll be denied access.”
Luckily our users have been able to enjoy this feature for the past few years for this exact reason. It feels great when ownCloud is ahead of the curve.