Closest I can find to an actual guideline against NSFW:
What you can't do
- 13 You can't, and will ensure that no users within a business account, of which you are administrator:
- 13.6 use our website, mobile apps, API, or any service, including, without limitation, any communication tools available through the website, our mobile apps, or our API, or any forum, chat facility or message centre that we provide:
- 13.6.1 to store, use, download, upload, share, access, transmit, or otherwise make available, data in violation of any law in any country (including to breach copyright or other intellectual property rights held by us or anyone else);
- 13.6.4 to store, use, download, upload, share, access, transmit, or otherwise make available, unsuitable, offensive, obscene or discriminatory information of any kind
3D artist ConnivingRat got all of his videos taken down, his account banned, and (if the error message is to be believed) his "full details, including IP address, have been provided to the authorities".
So yeah, maybe use Dropbox or Catbox or something.
Updated