Illegal content… well it depends. Illegal informations and piracy tricks? Already happening. But beyond that… illegal medias need to be stored and at large somewhere. It’s still better to do illegal shit on WhatsApp or Telegram (as it still happens) because messages, unlike here, are end to end private. I don’t think this is so novel, it isn’t in fact, that authorities or admins don’t know what to do. Also illegal is too generic. Laws vary from country to country as well. I don’t see Lemmy becoming any sort of terrorist hub anytime soon.