Users and mods have used it to detect sockpuppets and voting rings. We've had almost zero trouble with bots because of the invite system.
It's not obvious from browsing the site (though of course it's visible in the source: https://github.com/lobsters/lobsters/blob/791b21f60a2e952cab...) but users can lose the ability to invite if they reach a net score of -5 (rare, they have be a bad actor right out of the gate) or from a mod removing it (also rare, they typically have to invite several problem users or run a voting ring).
Users and mods have used it to detect sockpuppets and voting rings. We've had almost zero trouble with bots because of the invite system.
It's not obvious from browsing the site (though of course it's visible in the source: https://github.com/lobsters/lobsters/blob/791b21f60a2e952cab...) but users can lose the ability to invite if they reach a net score of -5 (rare, they have be a bad actor right out of the gate) or from a mod removing it (also rare, they typically have to invite several problem users or run a voting ring).