Were he actually present there for the duration of the entire mesiba, he would surely have recognized if strangers were invading his school and acting out. It should not take repeated complaints for several years to get the problem rectified, there or any other place.
the mashgiach was there for the entire party and would throw anyone out if they werent in yeshiva. i said that already. this party hasnt been going on for three years and you still complain about it?! mindboggling!! if there are kids who still make noise near yeshiva its probably not yfr kids anyways and the yeshiva has no achrayus for neighborhood kids making noise in front of your house