Dropbox has a futuristic vision for how its users will be able to share massive files and have quick access to them on their computers, without their hard drives overflowing.

Dropbox has just provided another reminder not to place complete faith in cloud storage, having allowed a bug to delete some users’ files.

Smart Sync is essentially Dropbox’s take on Microsoft’s placeholders, a former OneDrive feature that also let you view online-only files within Windows’ File Explorer.