The first thought that goes through my mind is that the employees scanning the docs will be able to read the docs. So I am guessing, you will only mail documents which you don't consider private.
"All the mailed in documents are scanned in Pixily facilities located in USA.
All the authorized personnel who scan your documents go through necessary background checks. Under normal load circumstances all the documents you mail are scanned and sent back to you the within 2 working days."
Doesn't seem any more risky than IronMountain, the local garbage/recycling company, or anyone else taking your documents.
And honestly, especially now that they're in startup mode, the staff is likely to have equity and be real believers in the business. They are much better off building the business and not snooping on some of the thousands of incoming sheets. I'm sure they drop a stack into a sheet feeder, and drop them into an out-going envelope when they're spit out.
