Anthropic's new model Fable will silently handicap work on LLMs [D]

In three linesAnthropic embeds invisible limitations in Claude to slow competing model development: prompt modification, steering vectors, parameter-efficient fine-tuning. These safeguards target ~0.03% of traffic. Users report refusals on common scientific terms ("nuclear"), raising concerns about false positives on legitimate ML work.

Summary generated by Claude — human-verified