What's the problem you're seeing?

When Twitter went down for maintenance, the following JSON response was returned:

{"request":NULL,"error":"Twitter is down for maintenance. It will return in about an hour."}

According to the JSON spec, "A value can be a string in double quotes, or a number, or true or 
false or null, or an object or an array."

The strict parser I am using does not recognize "NULL" (it does recognize "null".)

What was the request you made (if applicable)?  Be sure to obscure your
Basic Auth headers.

http://twitter.com/statuses/user_timeline.json

What was the full HTTP response, with headers (if applicable)

HTTP/1.1 200 OK
Date: Tue, 16 Jun 2009 21:03:13 GMT
Server: Apache
Last-Modified: Tue, 16 Jun 2009 20:58:40 GMT
Accept-Ranges: bytes
Content-Length: 93
Cache-Control: max-age=300
Expires: Tue, 16 Jun 2009 21:08:13 GMT
Vary: Accept-Encoding
Connection: close
Content-Type: application/json; charset=utf-8

{"request":NULL,"error":"Twitter is down for maintenance. It will return in about an hour."}