At 17, he is not a kid. He even admits in your article that he knew it was wrong. That proves to me that he should be as punishable for the crime as an adult who knows the law. I believe there is a real conflict of interest with your decision to run the Shell ads. What we really care about is whether the company really is turning over a new leaf.
Actions speak louder than words.
If Shell really were becoming greener, we would hear about it on the news, and the ads would be wasted money. Thank you for respecting my right to decide and your decision to not censor information. However, you probably shouldn't do the Shell ad. It belongs in your content like a fish belongs out of water. In your editor's note explaining why you decided to run Shell's ads, you assert that you respect and value free expression.