Every now and then someone decides the rules don’t apply to them and try to get unacceptable ads up. It’s usually not the ad carrier’s fault; these advertisers resort to various shenanigans to do this.
If you see an objectionable ad, I need some details. What it’s for, when you saw it, and which position on the page. Also the link URL if possible. If you can’t e-mail me (andy@…) us the “Contact Me” link above.