A community can be used for security of files rather than transferring them by email.
By way of an example a board of directors with some short term executive directors (these EDs have external email addresses) add board minutes and accounts to share with the board members.
By using Connections once an ED leaves they have no data pertaining to the company.
However they could download files or edit them in Docs and get an external copy(ies).
In the Edit Community settings sharing can be turned off for members. This needs to be extended for the option of turning off downloads or Editing (sometimes called Uploading).
Additonially some web sites prohibit Copy/Paste or Print Screen, this needs to either be universal in Connections or again be an option for the Owner to manage.