Every state had it's own laws but in general it is as follows (from Wiki article)
"Unlike other security interests, in most states, mechanic's liens are given to contractors and material suppliers who may or may not have a direct contractual agreement with the owner of the land. In fact, this is often the norm because in most cases, the owner of the land contracts only with a general contractor (often called a "prime contractor"). The general contractor, in turn, hires subcontractors ("subs") and material suppliers ("suppliers") to perform the work. These subs and suppliers are entitled to liens on the owner's property to secure their payment from the general contractor."
The customer DID order materials and labor to improve their property by ordering a satellite system. By law they are ultimately responsible for those expenses. Just because the cost of installation is amortized into the monthly charges for the service doesn't mean the customer doesn't have a financial stake in this.
As far as DirectTV being insulated from blame, in this case the shit runs uphill. Contractor to DTV to homeowner - someone will be made to pay, if you go for it.