During the late 1960's and 1970's there was a lot of fornication and adultery going on, not in just my Hall but the closest one as well.
As a guess this might have been because of the sexaul revolution era and the high number of young baby boomers at the time.
Today you might expect less of that because the age demographic in most JW Kingdom Halls which are made up of more older people.
As an example the PO in my Hall was a married guy with 3 kids, he traveled out town to do some business and while he was away from the family he was boinking young girls who he met at other JWS congregations.
He was eventuality caught and got DFed, this brought so much anguish to his family they moved away, really felt sorry for rest of the family.