回複：cable company's conractor lay a cable line without notifying

You need check your purchase agreement. Most homes when sold would include an easement reservation for utility/phone/cable companies. If your purchase agreement has such a clause, cable company has the right to come to your house and lay the cable. You may ask for the cost to repair the lawn. Without such a clause, the cable company likely committed a trespass. Eitherway, there is no privacy issue. Privacy is a group of torts which really do not concern this situation.