Note! This is part of a series on using IMPORTRANGE in Google Sheets. If you don’t know how to use IMPORTRANGE or what it is, I encourage you to head back to the first tutorial here:
And here is a link to the sample data that I am importing if you want to play along:
Template – Project Tasks (IMPORTRANGE)
You’ve grabbed data from a source Google Sheet and used the IMPORTRANGE function to insert it into your destination sheet carefully selecting the range and sheet tab of the data that you want to display.
So you might be thinking, Great! I’ve managed to only display the content from my original Google Sheet that I want my users to see and hidden the rest from them.
While this may be the case if you are only providing ‘View’ or ‘Comment’ permission to a Google Sheet, I do have an ugly little surprise for you if you.
Are you sitting down? Are you comfortable? Do you have a support network nearby?
Let’s have a look at the IMPORTRANGE docs:

So basically, if you have other editors on your new sheet editing your document, they can access anything in the imported Google Sheet by copying the access granted IMPORTRANGE. All they need to do is change the Sheet tab and the range location.