In other words, would participating in forum discussions on online forums (like reddit, thephilosophyforum.com, debate.org, etc.) count as an extracurricular. I understand that for something like reddit, it can be a little broad but I could specify which subreddits I like. For example, I like r/philosophy, r/history, r/AMA. The last one actually allows users to ask questions to celebrities like Neil deGrasse Tyson, who may actually answer your questions.
I feel online forums might have a stigma as being a place where the only things on there are rants and memes. But to be honest, there really are places in reddit where real intellectual knowledge and discussions can take place.
ECs:
Junior member at College Confidential.
Frequently post cake recipes on Facebook.
LinkedIn with Mariah Carey on LinkedIn.com.
Rated #23 on Instagram for best hip hop dance moves.
A friend of mine did have it on a college application, but she was a moderator and official advisor on an overseas forum similar to CC, and the application was for a graduate degree focusing on social media.
I’d see participating in Reddit subforums of the ones mentioned above as somewhere between good reading and discussions with friends. Useful and informative, but not the kind of thing you’d list as an EC.