Situations like this SUCK. Family that moved in behind me has a German Shepard and a Pug. They also have a doggie door, so they can come outside and bark whenever they want. We both have privacy fences, but if they hear us talk or whatever, they go ballistic. So I simply knocked on their door, and kindly asked them to bring their dogs inside when they begin barking at us, when we're outside trying to enjoy the privacy of our yard. Told them we have two daughters that like to swim, and we'll be outside all the time during the summer, and we would prefer not to have to listen to dogs barking non-stop. They were apologetic, and said they would take care of it....and they have. So we got lucky.
If they wouldn't have? I don't know what we would have done. Video tape it every time we went outside, and take them to court? Maybe, I don't know. Regarding your friend RVD, I would suggest she install some camera's in her backyard...like the one's hunters use at their deer stands, etc. You can get them at Dick's Sporting Goods, Gander Mountain, etc. So she can capture what is going on, and use that against her neighbors in court.