I've been having a heck of a time accessing rooftops in both Hong Kong and Vietnam. Overemployment has caused a number of security positions to open up -- as many as four people per floor in a retail or commercial building. You literally can't step out of an elevator without having a couple people spot and question you. It's a bit nuts.
That being said, you can't keep a man down forever, and if there's a will, there's a way. I was happy to pop Stephanie and Frank's rooftopping virginity. It was remarkably easy.