Three police grab both wrists of man and are unable to effect a takedown until a fourth officer grabs the man around the neck from behind and pulls him to the ground.
Police officer uses a snapdown to control person resisting arrest. He initially grabbed the wrist only to prevent escape, then clinched and executed a snapdown, controlling the man with transitions and body positioning on the ground.
Security guards take down a man who has invaded the field at a soccer match. The guards hit him with their batons while restrained, and the crowd intervenes and attacks them in return.
The chief mistake by the guards was failing to appreciate how their actions may appear to bystanders.
A police officer struggles to arrest a man by wrist control alone. Two bystanders intervene and clinch with the man around the upper body. One of the former bystanders transitions to control the legs, and together execute a very effective takedown and control of the man. Throughout the takedown, the police officer continues to attempt some kind of wrist/arm control.
A man is seriously injured, possibly killed with a hammer. This illustrates how deadly such an item can be, and why a person wielding something like a hammer must be treated as a deadly threat.
MMA fighter attempts triangle choke from bottom ground position. His opponent raises and slams him into the floor, resulting in a knockout. This is exceptionally dangerous and would most likely result in death on a hard surface.
This can be avoided by using techniques which break the posture of the person attempting the slam and bring them back to the ground, or by abandoning the technique as below. The slam is attempted by the same MMA fighter as the above video:
Complacent police surround man and fail to maintain a safe distance or keep their weapons ready. The man is able to close the distance and stab multiple police, possibly killing one before he is finally shot.
A passenger intervenes to choke out a belligerent drunk man who is arguing with airline staff. The choke quickly and effectively ends the confrontation.
Multiple prison guards fail to control inmate with attempted wristlocks and OC spray. Inmate achieves what prison guards cannot and takes down a guard by grabbing their legs.
Pain compliance (OC spray and baton) are ineffective against this man, and the police involved lack the skills/ability to physically control him. Backup arrives to assist, but it appears that the man could have overpowered the two police officers in the meantime had he decided to.