In order for the police to trespass a person off a property does their have to be a complaint by the property owner? Does it differ between business and residential? For example I cite 2 videos I watched on youtube. In the first a couple officers confront a group of teens hanging out in an alley behind an apartment complex. There had been no complaint by the owner but the officers claimed trespassing in order to frisk the teens and order them to move on. Is that a technically accurate use of the officers power? In the second video a man had just bought an Arizona ice tea from a convenience store and was talking with a friend in the parking lot. An officer approached and demanded to know what the man was drinking. The man told him and held up the can in plain sight but the officer demanded that the man hand him the can. When the man refused the officer claimed the man was trespassing and used that as an excuse to arrest him and sieze the can. This despite that fact that the business owner had made no complaint nor was even aware of the situation.