Generally, the public sits behind the three foot wall until their case is called. They can approach and check in with a court officer, but must return to their seat. Only attorneys and police can walk into the arena.
There was a lull between cases while the court waited for the sheriff to produce inmates. The judge read his computer. The court officers turned to their cell phones for distraction. An enterprising spectator walked through the opening in the wall and up to the clerk's table, removing his file from the pile and returning to the audience and out the door.
No one stopped him or said anything. The clerk discovers the file is missing and everyone pieces together what happened.
The next case is called and the ADA asked for permission to approach the bench where the judge and clerk sit.
The judge replied, "go ahead. Obviously, no one's going to stop you."