The forum I co-administer also had a user like this. Super knowledgeable, helpful person, but with some ugly social bad habits that would occasionally rear up. They would get flagged occasionally in public, but their PMs were worse—they didn’t apply the same level of self-filtering and caution as in public. After several warnings and multiple suspensions, we ended up needing to ban them permanently. So I sympathize with the desire to block PMing for particular users. That said, in the case I’m talking about, I don’t think such a feature would have ultimately prevented this user from getting banned, due to their occasional sufficiently problematic behavior in public. But I can imagine there being users for whom a no-PMs policy would be effective and keep them sustainably engaged in a more harmonious community.
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