a minor gripe

I can't be the only person who gets majorly peed off with rude behaviour in cafes and restaurants, but yet another incident today has got me riled.
I hate it when you go to a cafe for lunch, and although it is quite busy there are tables becoming available now and again. Then, when you are almost at the front of the queue some ignoramus comes in with their friends and goes straight to one of the few available tables while their mates join the back of the queue. Then, some other sheep-like retard from the back end of the queue decides that's a good idea and does the same. With the result that the people who have just purchased their food are left stood with a tray and nowhere to sit while the smug dickheads do their utmost to avoid eye contact which to me indicates that they KNOW they are twats. My way of dealing with this is to go and sit right next to them, because I am nice and non-confrontational like that.
Other things that piss me off in eateries:
People who talk loudly on their mobile phone throughout the meal, especially if it is someone who is supposed to be having lunch with you.
People who cough and sneeze without covering their mouth/nose as they do so.
People who leave their mess all over the table in establishments that ask you to clear your own rubbish away.
People who allow their young children to run around the place annoying the hell out of everyone else so that they can have a quieter meal.

I am sure there are more examples but you get the idea.
Surprisingly though, the worst culprits for the things mentioned above are the older generations - you know, the ones who like to complain about the "youth of today" having no manners.