We fully understand your concerns about sharing a copy of your passport. You can read about why we need a copy of your passport, and how you can safely share it with us here.
The Dutch tax administration forces us to ask you for a copy of your passport. If you don't want to share a copy of your passport but still want to receive your refund, you can file a complaint with the Dutch Data Protection Agency, in name of yourself and vatfree.com, against the Dutch tax administration. If you file a complaint with the DDPA we can still process your refund request.
More information about how to file a complaint can be found in the document attached to this article, below.