It's extremely common for people to ask and answer questions with no code other than a link to http://jsfiddle.net or similar service. These of course are not appropriate. I have personally been unable to access jsfiddle for hours due to the site being down while browsing Stack Overflow.

In an effort to help educate people on why this is a bad idea and at the same time improve posts on SO, I suggest some measures be put in place to prevent it from happening.

For example, if the question or answer has:

• A link to http://jsfiddle.net/, http://ideone.com/, or any other site in a specified list
• No formatted code

...prevent it from being posted, with a message or link explaining why. There may be edge cases where it does make sense, so perhaps we'd need to allow the user to click through the message and post anyways, but at least they will have been warned/educated.

If we need to discuss whether or not "link only, no code" posts are problematic and not appropriate, then so be it - but I think it's obvious and that topic has been well covered. Is there anything we can do to prevent them and encourage people to put their code in their post?

This issue is very specific to jsfiddle, I would like to see something that directly addresses that. If another site becomes the defacto code demo site, then we can cross that bridge when we get to it or look for more general solutions to this ever growing problem. I think that awareness of the issue is key to preventing it, and people don't read the FAQ nearly enough as it is - we need some direct intervention.