I know that SE sites are designed to give more privileges to users as the users gain the sites' trust (through the reputation point system). This demotivates potential grifters as they have to spend considerable time to gain even privileges to do any real damage.
With that said, have there been any cases of grifters (with high reputation) causing major harm to any SE site? And if so please provide information on the situation and how it was solved or how it might be better solved in the future. I know that SE sites run scripts that check for systemic downvotes and I was wondering if it checked for any other kind of systemic abuse.
*Note I'm not talking about trolls who post the same question over and over or other abuse that comes from users with low reputation.