It's one thing when you program the downloader selectively to take only certain files that you might need for a project for instance, but when some of these characters get on there they sap everything available within a site and it just sucks out all the bandwidth allocated for that site for any given time period. This forces the site owner to have to pay extra (by bandwidth consumption after the allocated amount is reached) if that clause is within the contract. If its not within the contract then the host cuts the site off automatically. If you get several individuals doing this at any one given time, you can imagine the amount of stress put upon the bandwidth. The downloader usually allows people with slow connections to download something like 5 files at a time since the connection is slow, the more files you try to download at once, it strains and chokes the connection (bottleneck). If the owner of the site cant afford to keep the site opened and no one is helping to pay for the bandwidth, then what usually happens is that the site is forced to shut down because of a few greedy, must have all, leechers.