Planned what?

Talking Points Memo has a piece about anti-abortion protesters collecting the license plate numbers of people entering clinics.

What interests me about that story is the photo they used to illustrate it. It’s an AP photo credited to Duane A Laverty, and it shows people wearing huge red stop sign-shaped signs that read

STOP Planned Promiscuity

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What?? That’s a thing? I’d never heard of that before.

But I still haven’t, apart from that photo. I can’t find it via Google, including via News or Images.

I’m very curious about it, as well as very disgusted by it. Does anybody know anything? Who uses this slogan? Is it an anti-abortion slogan or an anti-contraception slogan?