Blocking AI Crawlers vs. Letting Them In: A Practical Defense Guide

Someone on Reddit recently shared that Meta's AI crawler hit their site 7.9 million times in 30 days — burning through 900+ GB of bandwidth before they even noticed. If that doesn't make you want to immediately check your server logs, I don't know what will. I spent last weekend auditing three of my own sites after seeing that post. Turns out, I had a similar (though less dramatic) problem. That rabbit hole led me to completely rethink how I handle bot traffic, monitoring, and analytics. Here's what I learned comparing different approaches to detecting, measuring, and blocking aggressive AI crawlers. Why This Matters Now AI companies need training data, and your website is an all-you-can-eat buffet. Meta's crawler (Meta-ExternalAgent), OpenAI's GPTBot, Anthropic's ClaudeBot, and dozens of others are hammering sites at rates that would make a DDoS look polite. The problem isn't just philosophical. It's practical: Bandwidth costs money. 900+ GB of crawler traffic on a small site is absur