gistfile1.py

time = "10 minutes ago"
if ((distance_moved *since* time) < 200):
    # Possibly return a 420 or 429 response code? Possibly not a 429,
    # since we might want to use that for actual API request rate limiting.
    #
    # http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#420
    response = {
        "error": "back_off",
        "error_message": "...",
        "latitude": 125.45,
        "longitude": 45.67,
        "radius": 800
    }

# Client consumes the error, turns off location updates and sets a proximity
# alert to re-enable location tracking when the device leaves the area.