Regarding the ownCloud service, where confidential data maybe stored, the first thing to do is to secure the frond end seting up an SSL security and force HTTPS connection so that your passwords do not circulate in clear text on the WWW. It’s take less than 10 minutes and that prevent some data leak. See
HowTo: Install ownCloud with SSL and Nginx on your CentOS server via ▶ HowTo: Install ownCloud with SSL and Nginx on your CentOS server – YouTube. I can do this thing in my debian server for less than a 7 minutes, but RHEL made everything to be “secure”, so in order to install some packages