A 15% service charge is usually mandatory for groups of eight people or more in the restaurant business? Why? Because of groups like this.
When a service charge is added to a customer's bill in a restaurant, it's not added because of the server per se. It's added because of the trouble in serving a large group of people. Large groups generally turn over slower, which bites into the server and restaurant's cash flow. Large groups put the kitchen and/or barstaff in the weeds because of the number of orders flooding through at once. There is a lot of orchestration and timing involved in serving a large group--getting their drinks, salads, meals, desserts, refills and checks to them all at the same time, without confusion, is a pain in the ass. And on a night when the restaurant/bar is completely swamped, the last thing you want to see walk through the door is a party of eight or more people who are intent on being assholes.
Gratuities are a reward-based payscale for people in the industry. Since a substantial portion of the waitstaffs in any given restaurant are comprised of students, the low hourly wage allows them to work full time without getting taxed to death. Most restaurants have a computerized sales system that then removes the necessary tax owed the government, based on a percentage of sales.
A good server can make very good money in the service industry. I should know; I chucked teaching in favor of tending bar and waiting tables. Of course, there's a flip side to people who don't think they should have to tip because 'restaurants should pay minimum wage' or 'restaurants shouldn't shove their operating costs on the public.' Getting served in a restaurant or bar is not a right; it's a privilege and anyone, server or bartender, can refuse to serve anyone at any given time. I'm not sure about the rest of you, but I remembered every single non-tipping butthead who ever crossed my path. If they crossed my path again, I refused to serve them. *shrug*
If the restaurant posted a mandatory service charge of 18% for parties of eight or more and these people didn't pay it, then they were right to be arrested. If you want to complain about the service, you don't go to a bartender--you go to a manager and you don't wait until you're paying the bill--you ask for a manager during the meal. The service charge was included on the bill; it's non-negotiable and perfectly reasonable. So this couple whining because they were arrested for theft? Let 'em whine. They tried to beat the system and lost.
What a freaking shame.
The pub was in the right.