I just wanted to share an experience I had this week with a customer. I've been in the business for over 15 years, and have had plenty of bad encounters. But, this one is by far the worst, and I'm curious to hear your opinions.
So...I work at a small local restaurant. In the colder months, we can only seat around 15 tables. We have a popular happy hour, and the dining room fills up quickly. Two gentleman arrive around 5:00. They are going to have 4 more join shortly. I should probably mention that I have waited on these people before. They don't tip well. By not well, I mean 10%. IF that. That's fine. I'm not going to change my level of service based on knowing they are bad tippers. I want everyone to have a good experience. The first two guys order a ton of happy hour items (including drinks) for the two of them. They tell me the others will be there shortly, and they are going to order another round of food for one of the couples. They tell me to put this order on a separate check. The food arrives, the guys are still waiting for their joiners. The guys order more drinks while they wait, and wait, and wait....
Finally, at 6:45, the couple they order the food for show up. Not far behind, a couple more joiners arrive. The woman from the joining couple orders the most expensive glass of wine we carry, and then orders one of our most expensive dishes. Later, she orders another glass of wine. Everyone seems very nice, and jovial. They seem to be having a great time.
They continue to drink, and they start getting rowdy. They are talking very loudly, cussing, and basically acting like they were at a bar. They were bothering other customers, and we had a family leave because of the language they were using. Just to clarify, I'm no prude. I've got a potty mouth

I have never ever seen this. There were other tables in the restaurant, and it was humiliating. Obviously he didn't tip, but the entire check was around $200. I made $6 off of the entire table. And, yes, they received good service.
I'm curious to hear of any other stories about negative experiences with customers. I believe that the customer is always right...89% of the time. But, there is a line, and at what point do you stand up for yourself?