Failing request to Reddit API

gistfile1.txt

{
  "args": {},
  "headers": {
    "Host": "httpbin.org",
    "X-Modhash": "x0a9j5773dbbad92a49689ff79eeb22bac92c0d59ce777f8ca",
    "Connection": "close",
    "Content-Length": "45",
    "Set-Cookie": "2xxxxxx1,2014-02-08T23:02:23,6xxxxxxxxxxxxxxxxxxxxb96dee0c08d9ec3d26b",
    "X-Request-Id": "4cf09cfa-c606-4dbc-a57c-1c6307671015",
    "User-Agent": "fooBot/0.1 by username"
  },
  "json": null,
  "origin": "71.193.160.4",
  "data": "api_type=json&text=foobar&thing_id=t1_cf9k3wa",
  "form": {},
  "files": {},
  "url": "http://httpbin.org/post"
}