Take a look really closely at the fine print of your user agreement; in my local area it is Comcrud and they have been known to cut folks off for what they determine, on a 'case by case basis', to be 'excessive use'.
In particular, they keep real close look at the upstream data, which is much more constricted in their network than download. But there is a 'limit' out there with all cableco's, since it is a 'shared' system, i.e., like a party line telephone. Bits you use are not available for use by other either in your neighborhood or even city-wide (depending on how they engineered the system).
DSL by comparision is limited on on your individual line/speed, the DSLAM (dsl access multiplexer) at either the central office or a neighborhood fiber hub, is generally a minimum of OC12 (600Mb/s) or OC48 (2.4Gb/x) handling some several hundred customers. Newer stuff is even OC192 (10GB/s). So, obviously don't have the constrictions that cablecos have.
