Free market economics!
Doesn't sound like a problem with my ISP hat on:
1) Moving 1GB TIFFs between work and home? That's a business function, and possibly a violation of the TOS. Anyway, try a PORTABLE HARD DISK!
2) Running a webserver? This is *specifically* against every ISP's TOS I've ever read. You should be paying for a business class connection.
Both of these functions, in actuality, sound like business functions, and therefore both probably require a business connection via the TOS. Subtract out those two, and there's no way your running into a problem. Of course, I do the same exact thing, and will switch to any ISP which lets me get away with it, but at least I'm *aware* that I'm treading on the contract.
160GB per month of bittorrent and usenet traffic. I'm sure there is absolutely no illegal content being downloaded there.
While I don't engage in illegal behaviors myself, I actually fully support the p2p media sharing. Keep it up! The media market is, by definition, a monopoly. One company controls a given album/movie, and no other. In this case, I don't consider similar works to be equivalent. Thus it's a monopoly, and it's virtually unregulated. At least illegal file-sharing has introduced true competition, albeit illegal, and has forced Hollywood to begin to *consider* reasonable and ethical business practices. I would have some sympathy if they were at least regulated as other natural monopolies are.
gareth, you must admit, though, that you are the pathologic worst-case user for any ISP, and you're a money-loser for them. They are within their rights to adjust their offerings to accommodate users like you. Of course, there may be other ISPs willing to carry your load in order to garner good publicity, and, by all means, stick with the cheapest solution!
This is a reasonable business strategy for Comcast, and it's fairly permissive, as indicated by readers in other countries. As it only affects a small, loud minority, it will surely be successful. Of course, it's a free market, and those who care will vote with their dollars, changing service to another provider. Can't find a cheaper offer? Perhaps Comcast is not being so outrageous for that location after all! Consider relocating to an area with more competition.
Also, as high bandwidth services such as streaming hi-def video, VoIP/video conferencing, and burgeoning software patches (Blizzard, Microsoft) become more widespread, more users are going to begin stressing the system, and this will become more and more or a sticking point for an increasing number of users. Comcast can surely do this now, however it will probably bite them in the future. Either other ISPs will be forced to do similar, or Comcast will be forced by competition to drop the cap. I foresee the former, as ISPs will require increased revenue through higher connection fees to justify investing in the infrastructure needed to carry those services.
In the interim, allow me to recommend moving into a Verizon area and getting FiOS. I keep my FiOS connection maxed, and Verizon has yet to complain/cap/threaten/limit me; and yes, that was a criterion for determining what city and state I chose to work/live!