What does it mean for a question to be protected?
Protected questions have the additional restriction that new users are not permitted to answer the question. Unlike locked questions, they can still be edited, commented on, and voted on. You can even vote to close them.
Why are some questions protected?
Questions are usually protected because they have attracted either spam answers or "noisy" answers such as "thank you", "this worked for me", or "I'm also having this problem" from new users who may mistake the site as a traditional forum.
Who can protect and unprotect questions?
- Diamond moderators can protect and unprotect any question, regardless of age or answer history.
- Users with the Protect Questions privilege (15k reputation on graduated sites, 3.5k on beta sites)
- can protect a question which is at least a day old, and has at least one answer by a new user (i.e. a user that currently has <10 rep on the site, or <110 rep if they have the association bonus)
- can unprotect any protected question which is at least a day old
- The system (via the Community user) will automatically protect questions if a certain number of answers from new users get deleted or are posted within a short time. See the last section for more info.
Who can answer a protected question?
Users with 10 or more reputation can answer a protected question. However, the +100 account association bonus is ignored for this check1, so users with the association bonus require 110 reputation to answer protected questions. In other words, all users must have earned 10 or more reputation on that specific site to answer a protected question.
The reasoning about this reputation limit discussed in Allow people to answer protected questions if they have earned at least some amount of combined SE rep
When should I protect or unprotect a question?
- Do protect questions that are attracting a lot of non-answers or very poor answers (spam, etc.) from new users.
- Don't protect questions just because they're linked to on Hot Network Questions or a high-traffic news site.
- Do unprotect questions that aren't currently attracting a lot of attention and don’t have a long history of unproductive answers.
See also: Changes and guidelines for the Protected Question status
When does the Community user protect a question?
The Community user will protect a question in the following cases:
- The number of deleted answers from low-rep users, plus the number of answers with helpful spam flags, is at least 3. (Note that spam answers from new users are counted twice.)
- Generally, this means that three deleted answers from new users will cause auto-protection, but if at least one of those answers is spam, only two answers will trigger it.
- Five answers from low-rep users were posted in the last 24 hours. Three answers on Software Engineering, English Language Learners, and Workplace, and 20 answers on Code Golf.
The system will never unprotect a question automatically, even if the deleted answers are later undeleted or the spam flags are cleared.
Automatic protection notes
- The "low-rep user" check for auto-protection is different from the check for answering. Users with the association bonus but less than 110 reputation don't count toward auto-protection, even though they aren't able to answer such questions.
- Multiple answers from the same user are counted as just one towards the checks. For example, if three answers from new users are deleted, but if two of those answers were posted by the same user, the question won't be auto-protected unless it gets another deleted answer from a different (third) low-rep user.
- The checks are run whenever any answer from any user is deleted (for the deleted answers check) or posted (for the posted answers check). This includes answers from high-rep users, so if a question, for example, has three deleted answers from low-rep users but was unprotected later, if an answer from a high-rep user gets deleted, the question will once again be auto-protected.
- Sites have the ability to turn off auto-protection if they wish. Some per-site metas, especially those with "sandbox" questions, have opted to disable auto-protection.
1 On per-site metas, this restriction does not apply; if you have the association bonus, you can answer protected questions on per-site metas without needing to earn 10 rep on the main site first (provided your reputation on the main site hasn't dropped below 10).