A simple way is just to add a obvious warning - for example:
   > **WARNING**<br>
   > This may work, but will likely cause your system to become insecure. *Explanation.* *[Helpful link](http://meta.askubuntu.com/q/12049/178596)*.

This would be more helpful if this included a link and a short explanation *(preferably a SE one, so it is likely to still exist later on)* which explains the issue *(in this case, what happens to security if the password prompt is removed)*. This is helpful if this is in the answer itself, as sometime people may not look at the comments.

If it says to do something stupid - install dodgy programs etc - flagging for deletion or something else may be best.