Need some Advice: Creepy Gut at Work

There's this guy at work who literally has no one in his life. He's around 40-45, used to live with his parents, they both passed away a year ago. No SO. No real social life from what I can tell. Just work and his friends at work. Well, I recently found out that when he offers to take photos at work events, he tales pictures of the girls (only 3 of us in our group) and saves them on his personal drive. I found out because he told showed another coworker, who told me in confidence and asked me not to tell anyone. I know what he does is completely unacceptable and needs to stop. But I also don't want to ruin his entire career. That's all he has. I told the Co worker who told me about it to tell him how disgusting it is and that he needs to stop. Idk. I'm conflicted.