I would create a website and/or app for people to learn media competency. I know it does not sound so much like open source, but there should be a practical learning path including sending you phishing mail to test your recognition skills, such services should be open source. And it should teach how to avoid being influenced by FLICC based disinformation including how you recognize it in social media and meme like images.
Also learnig how to discuss and behave in online discussions would be nice. That includes recognizing trolls and socket puppets.
Hell I wish there was something to teach my parents, who ride every disinformation wave out there. I'm only glad they did not fall for phishing or internet scam. But it needs my constant attention. There are so many people out there who are not ready for the web.