Accidentally found a serious website bug. What do I do now?

I just created an account on fedex.com to print a document. In the "My Online Documents", I found there were already some documents uploaded. These documents are not mine and include PDFs of someone's ID card, unemployment insurance applications, and other personal documents. I'm looking at their DOB, email, phone, address, details of their termination, their previous salary, etc.

Where do I go from here to make sure this is properly investigated?