Unlearning Fails: Most AI Knowledge Removal Techniques Leak Through Probing
Researchers probed six Llama‑3‑8B checkpoints unlearned by popular methods and found that most techniques let hidden knowledge resurface—up to 64% recovery on some checkpoints. Simple fine‑tuning on unrelated data restored performance, and forced‑choice accuracy over‑estimated forgetting. The work warns that current unlearning offers a false sense of safety.