Always Lurking: Understanding and Mitigating Bias in Online Human Trafficking Detection

TL;DR

This paper presents a trafficking detection system that leverages AI to identify online human trafficking activities, analyzes biases in the detection process, and implements mitigation strategies to improve fairness and effectiveness for law enforcement use.

Contribution

It introduces a comprehensive detection pipeline, conducts bias analysis, and develops a bias mitigation plan, integrating an interpretable AI solution into a large-scale law enforcement tool.

Findings

Automatic detection aids law enforcement efforts.

Bias in AI models can affect detection fairness.

Bias mitigation improves system reliability.

Abstract

Web-based human trafficking activity has increased in recent years but it remains sparsely dispersed among escort advertisements and difficult to identify due to its often-latent nature. The use of intelligent systems to detect trafficking can thus have a direct impact on investigative resource allocation and decision-making, and, more broadly, help curb a widespread social problem. Trafficking detection involves assigning a normalized score to a set of escort advertisements crawled from the Web -- a higher score indicates a greater risk of trafficking-related (involuntary) activities. In this paper, we define and study the problem of trafficking detection and present a trafficking detection pipeline architecture developed over three years of research within the DARPA Memex program. Drawing on multi-institutional data, systems, and experiences collected during this time, we also conduct post hoc bias analyses and present a bias mitigation plan. Our findings show that, while automatic trafficking detection is an important application of AI for social good, it also provides cautionary lessons for deploying predictive machine learning algorithms without appropriate de-biasing. This ultimately led to integration of an interpretable solution into a search system that contains over 100 million advertisements and is used by over 200 law enforcement agencies to investigate leads.