25. I have downloaded images from a website situated in the United States. Which country's law would be used to determine whether or not I have infringed a copyright – US law or Hong Kong law?

Generally speaking, the question of infringement is governed by the copyright law which is applicable where the act in question takes place. When you download images from a website, a copy of the images is created on your computer. Your act of copying thus takes place where your computer is situated i.e. in Hong Kong. Therefore, the applicable law for determining whether your act infringes copyright is Hong Kong law.