Specific examples would be great as I am building a web app in Django right now that I hope will have a lot of untrusted users. Certainly I can point to example

Specific examples would be great as I am building a web app in Django right now that I hope will have a lot of untrusted users. Certainly I can point to examples of apps (such as http://disqus.com/ http://disqus.com/) who use Django extensively and have lots of untrusted users.