Office365 is a really robust cloud solution with strong security. There is no chance for hackers to break into your account unless your employees grant the access to the outsiders. Still the data loss may occur while migrating data from your local servers or other cloud-based applications like Google Apps.
Office365 users usually migrate their data from older desktop versions of Exchange and Sharepoint or from other cloud solutions. They can do it manually or use some third-party applications for this purpose. And this is where the data loss may occur due to these apps’ errors or inappropriate configuration.
In order to be able to apply these third-party solutions you have to give them specific permissions. If they do not have enough access to your data they just wouldn’t be able to do their job. And the fact is that by giving them these permissions you also allow them to change the content and even delete your users accounts with all the data.
Office cannot tell which command is right and which is wrong. Office is unable to tell the right thing from wrong. The program is given the command to overwrite the information, and only a living person will know which data cannot be erased.
And this is exactly where you as the business owner should be very-very careful, because these migration errors can significantly disturb your business processes. Just think for a moment what it would cost you to restore an entire account.
The best way to protect your data is to carefully plan the whole migration process. There are tons of articles in Office communities on how to do that. And do not forget to implement the apps like Upsafe free Office365 backup tool to make reserve copies of your data and to be able to restore it without much pain.
But keep in mind also that such kind of apps are the third-party apps just as well and you will have to give them access to your data anyway.