Before Women’s Equality Day on August 26, the YWCA wanted young people to become aware that sexualization in popular media contributes to violence against women, and that they should think critically about the content they watch online.

And, since they’re a non-profit, they wanted to do it in a cost-effective way.

To help the YWCA deliver the message, Rethink looked at the most popular content on YouTube: music videos. What the agency found were endless illicit music videos with no content warnings for young viewers. It also found a lot of advertising. So the team took that insight and decided to use it to their advantage.

Since YouTube won’t warn kids about sexually provocative content, the YWCA decided to do it for them. So the agency hijacked YouTube’s advanced ad targeting to run warnings disguised as unskippable six-second pre-roll ads. These unignorable warnings ran before music videos that objectify women— across all musical genres, and from the world’s most popular male and female artists.

Using YouTube also meant they could influence and reach the exact younger demographic it wanted, and get them to think critically about the content they watch just before they watched it. As a result, the YWCA “Ambush Advisories” were picked up by national news broadcasts, high-profile blogs and shared across social media. Across the board, it was applauded for calling out sexist content and trying to shift attitudes and practices that perpetuate the sexualization of women and girls.