I hate the utility company in san antonio. Not only can they not read a fucking meter correctly,  they cannot administer a webserver to boot. I sent this email tonight detailing an issue their server has had for over a year:

From: Jared Rodriguez <jrod@blacknode.net>
To: feedback@cpsenergy.com
Subject: Concerning cpsenergy.com
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Please have your technical staff configure your server to handle HTTP
host request for cpsenergy.com properly. At present, your server is
responding to requests inappropriately:

~ $ host cpsenergy.com
cpsenergy.com has address 208.188.159.143
cpsenergy.com mail is handled by 10 dmsmail.cpsenergy.com.
cpsenergy.com mail is handled by 5 mail.cpsenergy.com.

~ $ nc 208.188.159.143 80
HEAD / HTTP/1.1
Host: cpsenergy.com

HTTP/1.1 400 Bad Request
Content-Length: 39
Content-Type: text/html
Date: Thu, 21 May 2009 05:11:10 GMT
Connection: close

~ $ nc 208.188.159.143 80
HEAD / HTTP/1.1
Host: www.cpsenergy.com

HTTP/1.1 200 OK
Connection: close
Date: Thu, 21 May 2009 05:11:30 GMT
Server: Microsoft-IIS/6.0
Content-Length: 23019
Content-Type: text/html
Set-Cookie: ASPSESSIONIDAAQCDRCA=GFEKMIDCODDEABMGDIMHBIFI; path=/
Cache-control: private

I know IIS is crap, but you still should be able to configure it to at
least meet rfc standards. There is nothing wrong with the following request:

HEAD / HTTP/1.1
Host: cpsenergy.com

So the 400 error is just plain wrong according to rfc2616:10.4.1, which
states:

"The request could not be understood by the server due to malformed
syntax. The client SHOULD NOT repeat the request without modifications."

The server not handling client "Host:" header strings other than
www.cpsenergy.com is not a breach in HTTP header syntax, its a problem
with your implementation. Also, its really annoying to type
cpsenergy.com and get a 400 when any rational server would spit out a
301/2 to http(s)://www.cpsenergy.com, or a 200 and load some other
content. Its just plain lazy in my opinion.

Jared