From the Anabaptist Association’s weekly mail out - www.anabaptist.asn.au
One of the earliest of the Anabaptists, a Swiss Brethren named Conrad Grebel, defined the church to be “the few who believed and lived right.” Do you see the house church in that definition? Grebel would have been completely happy to see the great masses of unregenerate people who had flooded the state churches of his day walk out and never come back. He wanted to bring the church back to the way it was in the first century, before the corruption of the state church that can be traced back to the Roman Emperor Constantine in the fourth century.
http://www.hccentral.com/gkeys/ccult.html