when i was in my first internet community-- which was a well-moderated space-- my parents were concerned i was Talking to Adults. what they meant by this was that lifetime channel had recently done a couple movies in a row about internet grooming and murder, where isolated young girls were lured to meet much older men (who had lied about their own age) in person.
despite being a child of the 80s whose parents, understandably, had no experiential basis for teaching internet safety, i knew internet safety. no real name, no real location, don't share your age more than a rough range if at all, etc. why did i know those things? because adults in my first fandom communities taught me and other kids who showed up in those forum and chat spaces. they moderated or deleted messages that shared too much, laid ground rules, shepherded us. i knew those people in community, not in isolation (another tip the forum babies were given).
when my parents tried to ban me from all fandom internet-- a thing that was 80% of my social experience, as a rural, autistic, homeschooled teenager-- i posted a farewell in the forum (after a whole day of angry crying and arguing). one sweet member of the forum was a 20-something mom with two toddlers, and she wrote a lovely letter for me to print for my parents explaining how the community was moderated and what a benefit it could be and offered her own email and phone number if they wanted to chat.
they didn't reach out to her, but that letter is why i was allowed to stay online. just having the offer and the explanation was enough to reassure my parents. i wasn't besties with this woman, just a casual friend in the same space, but we stayed in touch. i respected her and the advice she and other adults in that community gave and it kept me safe in other interactions going forward
i'm friends with many of the people from that community on facebook now. they're still friends with each other. that kind woman? i watched via internet as her kids graduated. she watched me get married and have my own kids.
one of my older friends in another fandom was in her thirties when i got my driver's license as a teen. she celebrated with me. she sent my oldest kids a baby shower box that contained blankets that became their special blankies they still have saved somewhere as teens.
those relationships have been some of the most important ones of my teen years. they were people who enjoyed fandom chats with me, but also invested in me as a PERSON and not just as a kid they were tolerating. in the right context of healthy friendship, their advice and perspective kept me safe and helped me grow.
of course there are red flags kids should be taught for any relationship, but to stigmatize friendships across generational gaps harms kids more than it helps them. kids NEED friends that cross those spaces.