This code is beyond awful - it fails to display, makes endless AJAX requests, and more; here are a few fun tidbits:
1. The code is not encapsulated in an IIFE, so it clobbers any global variables (like 'image_url') in the page, breaking any scripts relying on those variables.
2. The code spends an inordinate time checking if you're running Netscape Navigator 6.
3. Strangely, they include a whole bunch of code allowing the message to be dragged around the window (which is nice) but they don't allow it to be closed. Of course, it closes itself after making a single AJAX request into a black hole, so there's that. Bugs piled on top of each other make this entire message mostly harmless, if it weren't for the variable clobbering & bandwidth usage (see the next item...)
4. Upon load, checkBulletin() is immediately invoked. This does an AJAX call to '/e8f6b078-0f35-11de-85c5-efc5ef23aa1f/aupm/notify.do?dispatch=checkBulletin'. I assume this is to check if the bulletin has changed, to see if there are new messages, or maybe to check if the user has acknowledged the message yet. Unfortunately:
* This URL is relative, which means it will never actually reach its intended target (instead filling your web logs with this request)
* Upon xmlhttp.readystate=4 (request finished, successful or not, so this will change to 4 even on a 404 error), the comcast message is hidden. This means that the entire 'bandwidth exceeded' message will actually be hidden as soon as this request completes, which may be in * The author makes an attempt to not continue sending AJAX requests to this URL after a successful attempt, but botches it, so this request is actually sent indefinitely, every 5000ms, while every any page is open. This means every single tab on your system is popping AJAX requests every 5 seconds for the whole month that your account is nearing its quota. This likely brings you over quota pretty quickly if you leave your computer on all day.
That's right, this code causes every page served on your system to pop an AJAX request to the wrong URL every 5 seconds, as long as the tabs are open.
We can sit and argue all day whether or not it's ethical to display messages by injecting code into the DOM, but it is certainly unethical to write such awful javascript that clobbers global variables and drives up bandwidth costs by making AJAX requests to the wrong url every 5 seconds until the cows come home. Whoever wrote this script should be fired.
EDIT: Similarly, back in the dialup days, some ISPs would inject ads into their content. One way this was stopped was to argue that it was not legal for the ISP to charge you for data, then artificially inflate the size of that data by injecting ads. This script is doing just the same in a measurable way by causing these AJAX requests to be run every 5 seconds on every tab in your system.