The worst I have seen on this forum was the incident where some witlesses were exposed last summer for eating the baby, and when they hide it by saying that the perpetrator was inactive, disfellowshipped, not baptized, or weak when they were not.
I have personally witnessed slander. One person was set up for a business fraud, where he lost $5,000 on that business for the scam. The other hounders tried to turn it around to make it look like he committed the fraud, and publicly reproved him for it. Within a year, slander spread that he was disfellowshipped (which was a blatant lie, since I was at the boasting session when he was reproved and embarrassed).
Another situation I have seen (and been victim of) was the slimebag that dragged me into the cancer added his own rules to the rules in the Suffer Forever book. First, he would not take no for an answer. He had zero tolerance for my having anything to do with the holidays, and went way beyond even the Filthful and Disgraceful Slavebugger in where he drew the line as its being a die-able offense. He wanted me to throw away all my music, not sell them--and told me that Michael Jackson disassociated himself in 1985 (instead of 1987), and that listening to his albums that I already owned, free and clear was "supporting that apostate". He wanted me to get out in field circus at 9 AM, knowing that I would not likely get out of work until after 1 AM the night before (my first time out). He also tried specifying what types of personal care items I needed to use. All in the name of setting up a code by which I was supposed to serve Jehovah.