Summary: This article discussed how if you share a file or folder in OneDrive or SharePoint using the Anyone with a link option it changes the security to public anonymous access.
There are different levels of security when sharing a file or folder. The best practice is to never share a folder as it is very easy for people to either not communicate or forget that folder is shared and later on a file of high confidentiality is put in that folder which then exposes it to everyone.
When sharing a file or folder you should ask the question: Is this confidential? If so is this the best way to get it to someone. These are the options:
Anyone with a link is the same as saying anonymous access which is the same as emailing the file out, you just hope the link doesn't get shared around.
People in the United Church - only someone with a staff account, but this includes, UCC, Kairos or anyone that has a licensed account.
People with existing access - only people who have access to the library or site already will be able to get into the item.
Specific people - You can type in an email address and share the file or folder with one individual
This is also why it is important to review sharing on any sites you are an owner. You may have seen the ShareGate reports that come around asking people to review their links. This is done every quarter and is one reminder to people to keep security in mind when sharing anything.
You can also view external shares on any site you have access to by going to the site usage report in SharePoint. To get to it go to the gear, then choose site usage then scroll to the bottom of the page you should see the header SHARED WITH EXTERNAL USERS, this example the site has no external shares.
It is a little different with OneDrive, you need to log into your OneDrive on the web. Go to Shared on the left menu and choose BY ME. This will show you a list of everything in your OneDrive you have shared out.
Examples of what it looks like to share a file in OneDrive
The example below shows me sharing out my Video folder. In the screen below I can add a persons name if I want OR I can click on COPY LINK either way as soon as I hit one of the two buttons (copy link or Send) the system will remove all security for that folder and make it accessible by anyone. By default the sharing is set to ANYONE WITH THE LINK CAN VIEW, this should be changed to specific people OR understand that the folder going forward is open to anyone.
You can easily see who and what you have shared by going into your MY FILES section of OneDrive and look under the SHARING column. You will also notice on folders a little two person icon as well as under Activity it will tell you if you have shared anything. In this case the folder video was shared then I unshared it but the activity shows only when I shared it. As well as the test1 folder, it shows that I have shared that out.
To stop sharing go to the file or folder you want to unshare, then click on the three dots next to it and choose MANAGE ACCESS. Once in manage access go to LINKS and delete any links that are in there. This will remove sharing from this item.