If we were to open our ideas portal up to the public we would want an obscenity filter
We have marked this idea as Likely to implement.
That said, a potential workaround in the meantime is to set your Default idea visibility to "private," which would allow you to moderate ideas and change them to "public" once the content is "approved." You can learn more about this feature here: http://blog.aha.io/index.php/increase-product-feedback/
You won't be notified about changes to this idea.