I am all for this. I'm a mother of three - 15f, 11m, and 9f. I have also been a teenager and young adult, and I know that teens and YA's feel (correctly) that they have the right to make their own life decisions, and they are going to make their own decisions with or without parental approval.
My parents were seriously strict, so when I decided to start experimenting with drugs, I was completely uninformed. One of the first things I tried was datura - what we called moonflowers. They grew wild in the part of Arizona where I lived. My mom was also uninformed, so when I found out people paid money for that stuff because it was a hallucinogen, I planted a giant garden of it and made serious drug money right under my mom's nose. The only reason my curiosity about "moonflowers" didn't kill me or leave me retarded is because I was smart enough to learn all I could about it from the people I was selling it to, and was very cautious about trying the absolute smallest amounts at a time.
The way I see it, my biggest job as a parent is to keep my kids safe until they reach adulthood, and my second biggest job is to teach them how to keep themselves safe. The third most important job I have as a parent is to teach my kids how to be healthy, happy, functional, responsible people, so they can have the skills and characteristics that will help them have happy, functional, fulfilling lives as adults. Teaching them what they need to know to make informed decisions for themselves, goes a lot farther toward those parental goals than trying to make those decisions for them. And if my kids know that their safety is more important to me than some moral judgement about them trying drugs or alcohol, then they know they can keep me informed so I can help make sure they are safe.
I have taught them what makes various drugs dangerous. I have also taught them what to do to make it less dangerous, in terms of each drug specifically, and in terms of situations that can make experimenting more or less safe, in case they decide to try any drugs anyway. They know they can call me for help if they get themselves in a bad situation, or if they're feeling bad effects from drugs or alcohol. They know they can tell me what it was, so I can make sure they get the right kind of care immediately.
My son and younger daughter are still pretty young, and drugs isn't a thing with their peers yet. But my 15 year old is getting curious, and she has been honest with me about it. She wants to try weed, but she has decided to wait until next summer, so that she can learn how it affects her before it can affect her at school. She said she'll let me know before she tries it, and where she'll be, and with whom. If that goes okay, she wants to try shrooms - same plan - during the summer, keeping me informed the whole way. She is making careful, informed decisions about it to keep herself as safe as possible. Why should I complain about that? She's a solid kid, exploring a natural curiosity in the safest, most responsible way she can.
I wish more kids could do the same. We need these posters. It would save some lives, maybe save some kids from getting hooked, doing more than they should secretly. And forbidden fruit is always sweetest - informing kids about drugs rather than forbidding drugs might take some of the appeal mystery and secrecy away from the whole idea of drugs.