Complete security policy with mentions of remote code

SECURITY.md

@@ -1,6 +1,40 @@
 # Security Policy
 
+## Hugging Face Hub, remote artefacts, and remote code
+
+Transformers is open-source software that is tightly coupled to the Hugging Face Hub. While you have the ability to use it
+offline with pre-downloaded model weights, it provides a very simple way to download, use, and manage models locally.
+
+When downloading artefacts that have been uploaded by others on any platform, you expose yourself to risks. Please
+read below for the security recommendations in order to keep your runtime and local environment safe.
+
+### Remote artefacts
+
+Models uploaded on the Hugging Face Hub come in different formats. We heavily recommend uploading and downloading
+models in the [`safetensors`](https://github.com/huggingface/safetensors) format (which is the default prioritized
+by the transformers library), as developed specifically to prevent arbitrary code execution on your system.
+
+To avoid loading models from unsafe formats(e.g. [pickle](https://docs.python.org/3/library/pickle.html), you should use the `use_safetenstors` parameter. If doing so, in the event that no .safetensors file is present, transformers will error when loading the model.
+
+### Remote code
+
+#### Modeling
+
+Transformers supports many model architectures, but is also the bridge between your Python runtime and models that
+are stored in model repositories on the Hugging Face Hub.
+
+These models require the `trust_remote_code=True` parameter to be set when using them; please **always** verify
+the content of the modeling files when using this argument. We recommend setting a revision in order to ensure you
+protect yourself from updates on the repository.
+
+#### Tools
+
+Through the `Agent` framework, remote tools can be downloaded to be used by the Agent. You're to specify these tools
+yourself, but please keep in mind that their code will be run on your machine if the Agent chooses to run them.
+
+Please inspect the code of the tools before passing them to the Agent to protect your runtime and local setup.
+
 ## Reporting a Vulnerability
 
-🤗 We have our bug bounty program set up with HackerOne. Please feel free to submit vulnerability reports to our private program at https://hackerone.com/hugging_face.
+🤗 Please feel free to submit vulnerability reports to our private bug bounty program at https://hackerone.com/hugging_face. You'll need to request access to the program by emailing security@huggingface.co.
 Note that you'll need to be invited to our program, so send us a quick email at security@huggingface.co if you've found a vulnerability.