Anything that unnecessarily initiates web requests and increases your data usage when you're applying data caps and usage overage fees smacks of fraud.
Of course, Comcast will simply claim "Oops! Bad coding - my bad!" and probably be allowed to walk away with little more than a 'stern' talking to, a slap on the wrist, and a relatively minor fine.
Problem is, nobody in the web world (who is providing online
anything) will be very anxious to point the finger or start screaming about Comcast since the amount of flaky, poorly written 'request' code very likely accounts for a
significant portion of today's overall web traffic.
So the last thing anybody using Ajax or related technologies wants is to be held accountable for whatever unnecessary bandwidth they chew up. Bandwidth that the average Internet subscriber ultimately gets stuck paying for.
Like the holy writ says: Judge not lest ye be judged."
Words of wisdom. And never so true as when it comes to code - and coders.