No I wouldn't have called the police, I would have said it's ok I will get child out and gone and played on something else. Also explained to child that sometimes grown ups can be rude and do the wrong thing, but that is life. Mountain out of molehill would be my thoughts. I would also be interested to know if gender of the adult came into play, was the level of intimidation felt because was a man.

At the park, I can't be everywhere at once, I have no issues with the concept of another parent (a stranger in the context of this story) picking up my child and moving them in aid of playground harmony (e.g DS blocking the slide and refusing to move) - this notion that no person should touch your child without your consent is very dangerous to society in my opinion.

The guy in the story was in the wrong, even if the people on the swing were hogging it, that is life, you do something else you don't physically remove them - but a police matter no way.