Questions are usually [protected][1] when there is a slew of non-answers being posted as answers.

> [Protected](http://blog.stackoverflow.com/2010/06/new-protected-question-status/) questions have the additional restriction that [new users](/privileges/new-user) are not permitted to answer the question.  Unlike [locked](http://meta.stackexchange.com/questions/22228/what-is-a-locked-post) questions, they can still be edited, commented on, and voted on.  You can even vote to close them.

Examples include:

 - spam
 - Thanks!
 - I have the same problem, how can I fix it?
 - spam
 - I'm too lazy to get rep so I write a comment, so here's an a non-answer for the mods to remove.
 - I haven't read the FAQ, so here are more details for my question, posted as answer.
 - spam, spam and more spam

Usually in such cases, the question will be protected by a mod, a high rep user (15k and up). The [Community user](/users/-1) will automatically protect any question where three answers posted by [new users](/privileges/new-user) have been deleted.

You cannot simply trigger protection via a flag, however, as a real person must accept your request and follow through with protecting the question. However, if you believe a question should be protected, flag for moderator attention and someone will look at it.


  [1]: http://meta.stackexchange.com/questions/52764/what-is-a-protected-question/52765#52765