ITHAAPUDDYTAT said:

because there is a filter in the line outside between your house and the street box, somewhere, that has a cyndrical filter installed that prevents higher channels from entering your house.
THat is somewhat true.
They must put a filter on the line to block out anything more than the basic service, however with digital boxes being addressable, changing the services allowed by the box, is done by computer.
It is much easier to steal cable in an apartment or condo than opening the box on the street for many residences.
The filter is made so that it is difficult to get off. You cannot unscrew it.. however with a strong quick tug, using pliers / vice grips, you can pull it off without damaging the cable ends.
It some communities, there are cable boxes outside the home which can be opened with a special tool the cable guy carries. This tool cost approx $40 and is available for sale if you know where to go!!.. as is the proper tool to remove the filter or block. (the cable company will put a block on, which is "tamperproof", but defeatable, when they disconnect your cable)
If anyone has a mod for the digital Shaw box, I would be interested!