[z3c0]

I'm curious if you've actually worked with surveys before, because this is how statistics work. All self-reported data has a bias based on a user's willingness to reply, and considering that predisposition as a variable is required.

This is the exact reason that crime statistics are so crummy, even from anonymous surveys. Very few are compelled to admit to a crime that they haven't been convicted of (and some won't even to admit to that). Or why post-sale NPS scores have a negative bent - you're more likely to respond if you have a complaint.