Story Time: So new player joins the group, I know they are trouble but they are related to another player or "everyone's best friend". So no chance to get rid of them.
Example 1- the group comes to a small way inn and meets the npc owner with a problem. Joe wastes no time murderhbobing the NPC and looting the inn. The group just shrugs. They stay the night at the inn...and find NPC owner alive and well the next morning. Joe is supper mad. He throws a tantrum, has his character kill the NPC...again. The rest of the group heads off to do the 'problem' anyway. Joe can't do much disruptive in the wild, but he does get three of his characters killed. The group takes care of the problem and heads back to the inn. Of course, NPC owner is alive and well...again. Joe gets really mad has his character kill the NPC, again. Then the same NPC comes in another door. Joe gets even madder, kills the NPC again. It only took five times for Joe to leave the game screaming he would never play with me again.
Example 2- Spoony- The game starts off with dinner at the kings castle...and problem player Mike. All the character sit down for a meal and about a minute into the game Mike tries to steal the kings golden soup spoon. Except the spoon animates and gets away from the character. For the next couple minutes Mikes character runs all through the dinning hall, kitchens, and other nearby rooms trying to catch the spoon. The spoon knocks tapestries down on him, throws knives, knocks over furniture and more endless slapstick. All the while the king pulls out his silver spoon ("I was born with this one") and calmly talks to the other players. I keep the side with the good players nice and clam, as they talk to the king. At first the good players ignore Mikes Mess, even with the king slyly making comments every so often "I thought I hear something break in the kitchen". When Mikes mess moves back into the dining hall and the spoon starts dropping hanging shields on poor Mikes character.....Marcy looses it a bit. She turns to Mike, near screaming, "what are you doing your destroying the castle to get a spoon?". Mike just gets even more crazed. This goes on for a couple more minutes...until the spoon knocks out Mikes character with a halberd. The good players then accept the kings quest, and head off, dragging Mikes unconscious character with them. Once in the Wild, Mike can't do much to disrupt or ruin the game...other then getting his character killed over and over again. Though...best of all....the SPOON kept poping up everywhere to mess with Mikes character when they did try to disrupt something...making noise when he was sneaking around, cutting his rope when he was climbing, and so forth.
These remind me of the stuff those "RPG Horror Story" Youtubers like CritCrab and DnDoge read off Reddit.