Stop VF from serving posts with global TES takedowns

visibility-filtering/rules/registry.rs

@@ -12,8 +12,8 @@ use crate::rules::socialgraph_rules::{
     DropExclusiveTweetContentRule, MutedRetweetsRule, ViewerBlocksAuthorRule, ViewerMutesAuthorRule,
 };
 use crate::rules::tes_rules::{
-    DropLegalTakendownPostRule, DropLocalLawsTakendownPostRule, DropStaleTweetsRule,
-    DropTweetsWithDmcaMediaRule, DropTweetsWithGeoRestrictedMediaRule,
+    DropGlobalTakendownPostRule, DropLegalTakendownPostRule, DropLocalLawsTakendownPostRule,
+    DropStaleTweetsRule, DropTweetsWithDmcaMediaRule, DropTweetsWithGeoRestrictedMediaRule,
 };
 use crate::rules::tweet_flag_rules as tweet_flag;
 use crate::rules::tweet_label_drops as tweet_label;
@@ -120,6 +120,7 @@ fn base_home_rules() -> Vec<Box<dyn Rule>> {
         Box::new(DropStaleTweetsRule),
         Box::new(DropLegalTakendownPostRule),
         Box::new(DropLocalLawsTakendownPostRule),
+        Box::new(DropGlobalTakendownPostRule),
         Box::new(SensitiveViewerLoggedOutDropRule),
         Box::new(SensitiveViewerUnderageDropRule),
         Box::new(SensitiveViewerNoStatedAgeDropRule),
@@ -173,7 +174,8 @@ fn timeline_home_recommendations_policy() -> Vec<Box<dyn Rule>> {
 mod tests {
     use super::*;
     use crate::models::{
-        HydratedTweetCandidate, MediaFeature, TweetFeatures, Viewer, ViewerFeatures,
+        HydratedTweetCandidate, MediaFeature, TakedownFeature, TweetFeatures, Viewer,
+        ViewerFeatures,
     };
     use std::collections::HashMap;
 
@@ -263,6 +265,72 @@ mod tests {
     }
 
     #[test]
+    fn post_level_dmca_drops_on_timeline_home() {
+        use xai_core_entities::entities::TakedownReason;
+        let policies = Policies::new();
+        let candidate = HydratedTweetCandidate {
+            tweet_id: 1,
+            tweet_features: TweetFeatures {
+                takedown: TakedownFeature {
+                    reasons: vec![TakedownReason::Dmca],
+                    ..Default::default()
+                },
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+        let viewer = ViewerFeatures::default();
+
+        let timeline_home = policies.evaluate(SafetyLevel::TimelineHome, &viewer, &candidate);
+        assert!(
+            matches!(timeline_home.action, VfAction::Drop(_)),
+            "post-level DMCA must drop on TimelineHome, got {:?}",
+            timeline_home.action
+        );
+        assert_eq!(
+            timeline_home.decided_by,
+            Some("DropGlobalTakendownPostRule")
+        );
+
+        let recommendations = policies.evaluate(
+            SafetyLevel::TimelineHomeRecommendations,
+            &viewer,
+            &candidate,
+        );
+        assert!(matches!(recommendations.action, VfAction::Drop(_)));
+        assert_eq!(
+            recommendations.decided_by,
+            Some("DropGlobalTakendownPostRule")
+        );
+    }
+
+    fn tes_has_takedown_applied_drops_on_timeline_home() {
+        let policies = Policies::new();
+        let candidate = HydratedTweetCandidate {
+            tweet_id: 1,
+            tweet_features: TweetFeatures {
+                takedown: TakedownFeature {
+                    applied: true,
+                    reasons: vec![],
+                },
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+
+        let verdict = policies.evaluate(
+            SafetyLevel::TimelineHome,
+            &ViewerFeatures::default(),
+            &candidate,
+        );
+        assert!(
+            matches!(verdict.action, VfAction::Drop(_)),
+            "TES has_takedown with no country reason must drop, got {:?}",
+            verdict.action
+        );
+        assert_eq!(verdict.decided_by, Some("DropGlobalTakendownPostRule"));
+    }
+
     fn dmca_media_drops_recommendations_only() {
         let policies = Policies::new();
         let candidate = HydratedTweetCandidate {

visibility-filtering/rules/tes_rules.rs

@@ -91,6 +91,37 @@ fn viewer_in_withheld_country(
         .any(|c| c.eq_ignore_ascii_case(viewer_country))
 }
 
+fn is_global_takedown_reason(reason: &TakedownReason) -> bool {
+    matches!(
+        reason,
+        TakedownReason::Dmca | TakedownReason::HatefulImagery | TakedownReason::Unknown
+    )
+}
+
+fn has_country_takedown_reason(reason: &TakedownReason) -> bool {
+    legal_takedown_country(reason).is_some() || local_laws_takedown_country(reason).is_some()
+}
+
+/// Post-level DMCA / hateful-imagery / unknown takedowns, or TES `has_takedown`
+/// with no country-scoped reason left for the geo rules.
+pub struct DropGlobalTakendownPostRule;
+
+impl Rule for DropGlobalTakendownPostRule {
+    fn name(&self) -> &'static str {
+        "DropGlobalTakendownPostRule"
+    }
+
+    fn evaluate(&self, context: &RuleContext<'_>) -> VfAction {
+        let takedown = &context.candidate().tweet_features.takedown;
+        let has_global_reason = takedown.reasons.iter().any(is_global_takedown_reason);
+        let has_country_reason = takedown.reasons.iter().any(has_country_takedown_reason);
+        if has_global_reason || (takedown.applied && !has_country_reason) {
+            return VfAction::Drop(FilteredReason::UnspecifiedReason);
+        }
+        VfAction::Allow
+    }
+}
+
 pub struct DropTweetsWithGeoRestrictedMediaRule;
 
 const WORLDWIDE_COUNTRY_CODE: &str = "xx";
@@ -453,6 +484,118 @@ mod tests {
                 .evaluate(&crate::rules::test_context(&viewer_with_country("de"), &c)),
             VfAction::Allow
         ));
+        assert!(matches!(
+            DropGlobalTakendownPostRule
+                .evaluate(&crate::rules::test_context(&viewer_with_country("de"), &c)),
+            VfAction::Drop(_)
+        ));
+    }
+
+    fn takedown_candidate(takedown: TakedownFeature) -> HydratedTweetCandidate {
+        HydratedTweetCandidate {
+            tweet_id: 1,
+            author_id: 100,
+            tweet_features: TweetFeatures {
+                takedown,
+                ..Default::default()
+            },
+            ..Default::default()
+        }
+    }
+
+    #[test]
+    fn global_takedown_drops_dmca() {
+        let c = takedown_candidate(TakedownFeature {
+            reasons: vec![TakedownReason::Dmca],
+            ..Default::default()
+        });
+        assert!(matches!(
+            DropGlobalTakendownPostRule.evaluate(&crate::rules::test_context(&viewer(), &c)),
+            VfAction::Drop(_)
+        ));
+    }
+
+    #[test]
+    fn global_takedown_drops_hateful_imagery() {
+        let c = takedown_candidate(TakedownFeature {
+            reasons: vec![TakedownReason::HatefulImagery],
+            ..Default::default()
+        });
+        assert!(matches!(
+            DropGlobalTakendownPostRule.evaluate(&crate::rules::test_context(&viewer(), &c)),
+            VfAction::Drop(_)
+        ));
+    }
+
+    #[test]
+    fn global_takedown_drops_unknown() {
+        let c = takedown_candidate(TakedownFeature {
+            reasons: vec![TakedownReason::Unknown],
+            ..Default::default()
+        });
+        assert!(matches!(
+            DropGlobalTakendownPostRule.evaluate(&crate::rules::test_context(&viewer(), &c)),
+            VfAction::Drop(_)
+        ));
+    }
+
+    #[test]
+    fn global_takedown_drops_applied_with_no_country_reason() {
+        let c = takedown_candidate(TakedownFeature {
+            applied: true,
+            reasons: vec![],
+        });
+        assert!(matches!(
+            DropGlobalTakendownPostRule.evaluate(&crate::rules::test_context(&viewer(), &c)),
+            VfAction::Drop(_)
+        ));
+    }
+
+    #[test]
+    fn global_takedown_allows_country_only_legal_request() {
+        let c = takedown_candidate(TakedownFeature {
+            applied: true,
+            reasons: vec![TakedownReason::LegalRequest {
+                country_code: "de".to_string(),
+            }],
+        });
+        assert!(matches!(
+            DropGlobalTakendownPostRule
+                .evaluate(&crate::rules::test_context(&viewer_with_country("us"), &c)),
+            VfAction::Allow
+        ));
+    }
+
+    #[test]
+    fn global_takedown_drops_even_for_author() {
+        let mut c = takedown_candidate(TakedownFeature {
+            reasons: vec![TakedownReason::Dmca],
+            ..Default::default()
+        });
+        c.author_id = 999;
+        assert!(matches!(
+            DropGlobalTakendownPostRule.evaluate(&crate::rules::test_context(&viewer(), &c)),
+            VfAction::Drop(_)
+        ));
+    }
+
+    #[test]
+    fn global_takedown_does_not_consume_media_dmca() {
+        let c = HydratedTweetCandidate {
+            tweet_id: 1,
+            tweet_features: TweetFeatures {
+                media: MediaFeature {
+                    has_dmca_media: true,
+                    ..Default::default()
+                },
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+        assert!(matches!(
+            DropGlobalTakendownPostRule.evaluate(&crate::rules::test_context(&viewer(), &c)),
+            VfAction::Allow
+        ));
     }
 
     fn geo_candidate(allow: &[&str], deny: &[&str]) -> HydratedTweetCandidate {