It's been a madhouse at the courthouse ... when the trial first started, fans started to line up around 5 AM outside the building -- but it's now off the rails with Amber on the stand.
Fans started lining up at 10 PM Sunday for Monday's 9 AM start ... just to get a glimpse of Amber ... causing the Sheriff to post a sign the following day that read, "Effective Immediately the Line for the Johnny Depp and Amber Heard Case Spectators are Not Permitted to Loiter or Camp Out on The Judicial Complex Before 1 AM."
As for the process to score a seat, we're told court officials have about 100 wristbands to dole out -- on a first come first serve basis -- for the main courtroom and an additional 100-150 wristbands for the overflow room ... and still dozens of fans are turned away.
Our sources say there have been screaming matches when people cut the line. And get this ... there's even a black market with folks offering cash for wristbands.
The crowd is almost entirely supporters of Depp ... he's gotten a hero's welcome almost every day he's arrived. Safe to say, even if the trial doesn't go his way -- he'll still have plenty of fans to show their support.