It reminds me of the security guard paradox - companies that hire security guards rarely see break-in attempts, so they might be led to believe that the security guard isn't doing anything. But if they get rid of the security guard, they'll suddenly see break-ins - the security guard was discouraging would-be attackers. In the same way, it's probable that with the checks and balances in place to limit the damage that false accusations might do, one might look at the rarity of false accusations and say, "hey, this is practically never happening, we can loosen the restrictions here a bit" only to see it suddenly used as a weapon because it's now suddenly effective.