They're infiltrating 100%. There's no way to get around that. There's larping ajnabis on here right now. Their sus opinions give them away. Perhaps if there's an app back home, it could be limited to Somali phone numbers or something.
Proper moderation can cut down on trolling. If you have a system where reports are being taken seriously, you can ban troll accounts easy. Or you IP ban trolls so all accounts associated with them are gone. The problem with current tiktok and twitter is that they use AI for most of their moderation so things are never really dealt with and that one person can continuously be banned and they can still make dozens of accounts and get around that. Good moderation can also limit accounts that push FKD and gender wars by suppressing those topics or people that post about those topics.