Print this letter you just wrote and anonymously tape it to her front door. Actually wait until most the comments have rolled in and include those too.
There *is* an operation that can sever the vocal cords and quiet down an obnoxious creature. Not sure if the guy would agree to have it done on himself, though.
I had friends in a similar situation but in a different state. She is a law dog and knew the legal angle to take with the incessant barking of the neighborhood dogs. All of her neighbors hate her after she filed the appropriate paperwork, but at least the dogs are kept inside. Either go to court, or keep posting to IA. I'm not sure which will have a greater impact.