For what it's worth, at jtv we used to have a policy of silently failing various actions when one of our many spam-like flags got raised.  It seems like such a great idea - the spammers will have been caught, but they won't <i>know</i> it.  Unfortunately I think we've found over time that the negative consequences for users who are falsely flagged as being spammers just aren't worth it, and we have become more explicit about telling users they've been flagged in some way.<p>Long story short: If you're going to disable some action I think it's actually better in the long run to make it obvious that's what you're doing.