Here's a link to a story about a custody stand-off in McHenry County. Take a read...seemingly the issue was basically about a non-custodial father wanting more visitation.

The dispute apparently revolved around Gitchel (father) wanting further visitation with his daughter, police said.

What to do in this situation? Well, if you're the non-custodial parent I'd recommend having a certified copy of the court's visitation order with you at your pick-up time. Calling the police is an option because visitation abuse IS a criminal violation...however it should be a last resort. Probably a first step to avoid this type of blow-up would be to have visitation pick-up/drop-off at a neutral location which could be the police station.