The first reason is that these photos are the privacy of the stars. In fact, to a certain extent, these photos are photos that the stars don't want to make public, and they are also private photos of the stars, so they can't be leaked. Those that are directly leaked without the consent of the stars are very bad and violate the privacy of the stars, which is illegal.
The second reason for the photos is that these leakers use them for profit. Those leakers not only leaked these pictures, but also used them to sell their own interests, which is a serious violation of the law, a serious violation of the personal information of those stars, and a significant impact on the reputation or other rights of stars, which is against the law.
The third reason is that the law prohibits it. In fact, our laws have long prohibited this kind of behavior, and we can't let it happen constantly, because many laws will classify this kind of behavior as prohibited and mandatory, and we can't do it, and we can't seek benefits for ourselves in this way.
In a word, I think what the leaker did was illegal.