Met one of their evangelist, Helios, on SL (Second Life) a virtual internet environment. He recommended his New York fellow, Keith Canton at 10th Street. Part of the Church of Christ denomination, eventhough he's very against using "denomination".
They are those extremists but more mellow in reaching out kind of people. They probably don't shout or curse at non-believers or picking people out to challenge them. Extreme because they ultimately want certain doctrines such as baptism by immersion (form of baptism), etc. that they believe to be the same in order to be considered saved, or truly following God. I asked him any well known preachers they would identify with to invite to preach, he told me he couldn't think of one. At the same time he tried to show he's very open.
Of course, it is a matter of interpretation of the scriptures which would be time consuming if I had to go over those area with him. So I just asked him questions instead of debating on any particular subjects.
My own research points me to this group: Church of Christ. I think Helios mentioned Thomas Campbell as some major player but he also tried to emphasis they don't really have or follow any founder or someone of any significant other than Jesus Christ. A disturbing part in wikipedia is that they are those New Testament orientation believers, a major part Helios left out.