  There is a growing interest in developing unlearnable examples (UEs) against
visual privacy leaks on the Internet. UEs are training samples added with
invisible but unlearnable noise, which have been found can prevent unauthorized
training of machine learning models. UEs typically are generated via a bilevel
optimization framework with a surrogate model to remove (minimize) errors from
the original samples, and then applied to protect the data against unknown
target models. However, existing UE generation methods all rely on an ideal
assumption called label-consistency, where the hackers and protectors are
assumed to hold the same label for a given sample. In this work, we propose and
promote a more practical label-agnostic setting, where the hackers may exploit
the protected data quite differently from the protectors. E.g., a m-class
unlearnable dataset held by the protector may be exploited by the hacker as a
n-class dataset. Existing UE generation methods are rendered ineffective in
this challenging setting. To tackle this challenge, we present a novel
technique called Unlearnable Clusters (UCs) to generate label-agnostic
unlearnable examples with cluster-wise perturbations. Furthermore, we propose
to leverage VisionandLanguage Pre-trained Models (VLPMs) like CLIP as the
surrogate model to improve the transferability of the crafted UCs to diverse
domains. We empirically verify the effectiveness of our proposed approach under
a variety of settings with different datasets, target models, and even
commercial platforms Microsoft Azure and Baidu PaddlePaddle. Code is available
at \url{https://github.com/jiamingzhang94/Unlearnable-Clusters}.
