I don't speak SQL myself, so I'm not sure if this is a good example, but here is the question that prompted this query:
How to exploit the "PHP_MAGIC_QUOTES ON" vulnerability in order to cause max damage?
Asking for general conceptual how-tos is one thing (and even then, horribly fuzzes the white-hat/black-hat line around here), but postings that explicitly include exploit code are another.
Further, the wording of the question itself in this example still sets off the "black hat" alarms in my head. Perhaps a more acceptable phrasing would be "What is the maximum damage that could be caused by exploitation of this vulnerability?". Again, this brings the question to more of a theoretical abstraction instead of seeking a technically detailed attack implementation.
To what degree should we be filtering this, here?