Anthropic says defenses cut Claude reasoning token extraction 90 to 99 percent

Key points

• Anthropic restricts access to Claude's internal reasoning steps and runs a classifier that flags extraction attempts.
• Attackers reportedly use networks of hundreds of thousands of fake accounts to pull the data.
• Anthropic names Zhipu and Moonshot; Zhipu allegedly took cyber capabilities for its GLM-5.3 model.
• Tens of thousands of accounts are already banned, and Anthropic admits some legitimate users get caught.

Why it matters for marketers: Teams using AI tools should expect stricter account checks and automatic bans, which can disrupt legitimate workflows and need contingency planning.