Authentication is not mandatory for every requests to the Hub. For instance, requesting
details about `"gpt2"` model does not require to be authenticated. However, if a user is
[logged in](../package_reference/login), the default behavior will be to always send the token
in order to ease user experience (never get a HTTP 401 Unauthorized) when accessing private or gated repositories. For privacy, you can
disable this behavior by setting `HF_HUB_DISABLE_IMPLICIT_TOKEN=1`. In this case,
the token will be sent only for "write-access" calls (example: create a commit).  
**Note:** disabling implicit sending of token can have weird side effects. For example,
if you want to list all models on the Hub, your private models will not be listed. You
would need to explicitly pass `token=True` argument in your script.