A facility for providing access authorization is provided. The facility initially enforces a first, less restrictive policy when making its access control decisions. Subsequent to detecting an anomaly, the facility enforces a second, more restrictive policy when making its access control decisions. The facility returns to enforcing the first, less restrictive policy when the anomaly no longer exists. In another embodiment, the facility enforces a policy after detecting an anomaly and until the anomaly has ended.