From a risk$-$management perspective, a website that allows visitors to contribute content must

Ensure freedom from bias on the part of either the human or automated moderators used on the site.

Diligently monitor user$-$generated content on a $24$ hour basis.

Let visitors themselves inform the business about offensive or other inappropriate content posted by others.

Carefully define acceptable and prohibited conduct and content in its terms of use and$/$or in its privacy policy.