Phil Lord is correct that there is still a club called the Anti-horse theft Protection Society (or something like that!) in Rensselaer County. The organization was formed to deal with just what the club name implies. I am familiar with the use of the term Vigilance Committee in reference to the Underground Railroad. I belive that this was, literally, a committee of people keeping protective watch over and assisting escaped slaves. We had one of those in Rensselaer County also -- Troy, actually.