This is a running counter of web requests the WAM plugin denied. A rising trend here, independent of the accepted-requests counter, is what an admin uses to spot either a brute-force credential attempt against the protected application or a misconfigured policy that started blocking legitimate users after a recent change. For example, rejected requests jumping from a baseline of about 10 per hour to 4,000 per hour would indicate a credential-stuffing attempt against the application's login form.