Perplexity, an AI-powered answer engine, has been observed using stealth, undeclared crawlers to evade website no-crawl directives, ignoring robots.txt files and rotating IPs to hide their crawling activity. This behavior is seen as a breach of trust and incompatible with the preferences of the internet community. Cloudflare has de-listed Perplexity as a verified bot and added heuristics to block this stealth crawling. The incident highlights the importance of transparency and respect for website directives in web crawling.