We know that many of you are having fun with the gender-swap filter on Snapchat because admit it, it's pretty cool.

However, instead of having fun, one male college student in the United States decided to use the filter for the greater good: exposing online pedophiles.

Well, how did he do it?

According to a report by the NBC Bay Area, the 20-year-old, who is only known as Ethan, created a fake online persona called ‘Esther’ to catch possible pedophiles after hearing about how a female friend was molested as a child.

Ethan putting the filter app to good use.
Soon after, he reportedly started receiving messages from a man on dating app Tinder.

"I believe he messaged me, 'Are you down to have some fun tonight?' and I decided to take advantage of it," Ethan told the news portal.

Despite being told that ‘Esther’ was only 16 years old, the man proceeded to chat her up.

"We started texting on there, and it got a lot more explicit," Ethan said.
Shockingly, the investigators later found that the man was a police officer named Robert Davies.

According to the report, Davis was arrested earlier this week on suspicion of discussing sexual activity with a minor on social media. The disgraced officer has also been placed on paid administrative leave.

Well done, Ethan, for putting the filter to good use.