Recently I have experienced a lot of problems with KSAN (San Diego Itl.) users. Firstly, many Cessna pilots completely ignore all instructions. For heavens sake, a Cessna Citation X pilot kept on flying at 100 feet and passing extremely close to other airplanes! This issue needs to be tackled.
Secondly, patience. The aircraft there spam in the Tower frequency, insisting to be allowed to take off when there are many planes in a pattern, waiting to land! One Airbus A321 had to wait for 40 minutes to land due to a massive amount of users going on the runway without clearance!
Thirdly is one that you do without realising. At the moment, you can pass through any aircraft. No collisions means that people battle through other airplanes, just to be first in line! Someone has got to deal with this.
Lastly, is something simple. Sometimes, Air Traffic Controllers leave. This means for a moment, the frequency switches to Unicom. When a controller comes back, a plane may be landing while another plane is taking off. The controller attempts to make the plane go around. They say in the radio that they are going around, but instead completely ignore this. The plane then lands on top of another aircraft, which restricts vision and annoy pilots. If you have a similar issue, please contribute, and we will discuss this.