What would you do if you found out your four year old was handcuffed for.....

Well, my child was not handcuffed, but over the summer my kids go to my dads 3 states away for a month, one at a time and after my youngest (age 6) came home from his month visit, he told me that my 15 year old brother told him that he was not allowed to call me and his dad because we were all dead. When I found this out I was SO p!$$ed that he would tell my 6 year old this.
My son had JUST lost his best friend to death by getting hit by a car a month before he left to visit my dad. ALSO, while he was with my dad, my grandfather passed away and I still had not told my son that when I found out about what my brother told him. He told him that we all got hit by a car and all of us were dead.
My son had JUST dealt with losing a VERY close friend that was hit by a car and killed. He went to her funeral and everything and I could not imagine what the poor baby was going through when his 15 year old uncle told him that his mom and dad and brother was killed the same way!
So, needless to say, my children will no longer continue to visit my fathers home without me there.
I do not know why or how people can be so cruel, but they are and all that we can do is try our best to protect our children from these horrible people. AND teach our children a better way of acting. I explained to my kids how and why what their uncle did was wrong.
My father denies that my brother would do that, but my brother told me that he did it and that he was only 'joking', well, I do not find it funny AT ALL! My child had nightmares for months about it. He saw that little girl in her coffin after she died and he saw her bruises and her cuts all over her little face and hands and his daddy and I had a hard time helping him get through the loss of that little girl. She was his best friend in life and he talked about her everyday after school, he loved her and for his own UNCLE to tell him that WE also were killed the same way, when we were 700 miles away from him.... heartless.
I think that in your case, you should make a police report, they literally put handcuffs on your child and that is abuse. As for them telling your child that he would never see you again, I'm not sure that there is anything you can do about that, but I would FOR SURE make a report on them for cuffing your child.
Good luck to you!