World's Fair 2025
How to defend your sites from AI bots — David Mytton, Arcjet
Overview
This talk addresses the increasing problem of automated traffic on websites, exacerbated by the rise of AI. While bots have always existed, AI crawlers and agents are intensifying issues like increased costs, bandwidth consumption, and denial-of-service attacks. The presentation outlines various defense mechanisms, ranging from voluntary standards to sophisticated detection and mitigation techniques, to help site owners manage and control bot traffic.
Who should watch
- **Developers and Engineers:** Those building and maintaining websites and applications who are experiencing increased traffic costs or performance issues.
- **Product Managers:** Individuals responsible for website performance, user experience, and cost management.
- **Security Professionals:** Those concerned with protecting online services from malicious automated activity.
- **Anyone experiencing unexplained traffic spikes or increased infrastructure costs.**
Key takeaways
- Nearly 50% of web traffic is already automated, with AI bots significantly worsening this trend by making numerous requests for training or data scraping.
- AI crawlers like OpenAI's GPTBot are contributing to increased bandwidth usage and infrastructure costs for sites like Wikipedia and Diaspora.
- While traditional methods like robots.txt are voluntary and often ignored by malicious bots, they serve as a starting point for defining desired bot behavior.
- User-agent strings, though easily spoofed, can be a first signal, but must be combined with IP address verification against known bot providers for better accuracy.
- IP address reputation, including data center origins and VPN usage, provides further signals, though geo-location data can be unreliable.
- CAPTCHAs are increasingly vulnerable to AI, leading to the exploration of methods like proof-of-work, which requires computational effort before access.
- Emerging standards like HTTP message signatures and Apple's private access tokens aim to cryptographically verify client identities.
- Client fingerprinting, which analyzes network request characteristics beyond IP addresses, offers a more robust way to identify and block persistent automated clients.
Notable quotes
*Almost 50% of web traffic today is automated clients.*
*AI is making this worse.*
*The first one of these is it's not really a defense because it's entirely voluntary.*
Unofficial community note. Prefer the recording for nuance.