A couple years ago, one of my Japanese friends who used a dating apps warned her friends including me about the fake profile photos. She matched a good looking western guy in a dating apps. They exchanged messages for a while. But she was skeptical about him from the beginning as he was very handsome in his profile photos. On day, she googled images using his profile photos. She found out that the person in the photos was a politician from other country. That guy from the dating apps used this handsome politician's photos for his profile! From last year another Japanese friend started to use a dating apps. When she talked me happily that she matched a good looking Japanese guy and started to communicate with him, I told her about my friend's experience in a dating apps. When I talked her next time, she told me that his profile photos were completely stranger's. She also googled his photos and realized that they were the stranger's photos from Twitter.
If you use the service like us, this will never happen as we have an online-interview to all people and know their appearance.