The May 2003 Question Box in the KM has a little piece which demonstrates how the WT feels about the wishes of non-JW's.
When witnessing by telephone, what should we do if a person requests that Jehovah's Witnesses not call again?
The wishes of the person should be respected. A dated note with the name of the person should be placed in the territory envelope so that publishers will avoid calling that number in the future. Once a year, the list of people who have requested that we not call should be reviewed. Under the direction of the service overseer, experienced, tactful publishers can be assigned to contact these people to determine their current feelings. - See the January 1994 Our Kingdom Ministry Question Box.
OK, the first thing that jumps out here is the ridiculous self-contradiction of the answer. First they say that a person's wishes to not be called on should be respected, then they give instructions which basically say to call on that person anyway!
It's pretty obvious that when someone says "don't call me again", they're not saying "you can call me once a year to see how I feel." The Watchtower is showing contempt for people's wishes and forcing their religion upon those who have clearly expressed a wish not to be harassed in this way.
What about legal aspects? If a person sues the Watchtower for making a once a year call after a request that they do not call, it would appear from the above that the congregation's own files provide evidence that the person's right to be left alone has been violated. It would be interesting to see how a test case went.