What made Mr. Ross realize that he must end the experiment?

Eventually, teachers students, and even Mr. Ross' wife acknowledge that things have gone too far. Mr. Ross' group is out of control; they indulge in vandalism, terrorism of other students, and one of the students went so far as to appear at Ross' home like it was his own. Ross himself began to enjoy the experiment far too much; he enjoyed the power, the way the students looked at him, and the way they hung on is every word. Once he realized the entire experiment had escalated to a point where he could no longer reign the children in, he knew it had to end.......... it was a fast spreading cancer, and those involved learned a very important lesson about blindly following a leader.

Thanks Aslan. Would you be able to help me and take a look over my other questions? Or Maybe there's a way i can contact you so we can discuss them? Thanks