Original of the open letter to US Government: <a href="https:&#x2F;&#x2F;www.documentcloud.org&#x2F;documents&#x2F;2515596-final-drone-letter.html" rel="nofollow">https:&#x2F;&#x2F;www.documentcloud.org&#x2F;documents&#x2F;2515596-final-drone-...</a>