Moderation is an ultra hard problem so yeah its gonna be difficult. Nothing can really be bulletproof in that sense. Most types of controls can get evaded in some way.
That’s not to say that putting up some little hurdles won’t help. It at least solves the problem of automated signups (temporarily) and low effort trolling. If someone runs a coordinated attack i think that’s just going to be very hard to defend against.
I wonder if they accept PRs for lemmybugs. I guess they’re smashed with 1000 contributors right now. I’d love to help fix that kinda stuff.