Per the official rules, https://serverfault.com/privileges/protect-questions

Which questions can be protected?

 

Any question, even a deleted question, can be protected and unprotected, subject to the following restrictions:

 

• The question must be at least a day old
• A user can unprotect a question protected by him or herself, but not one that has been protected by someone else

So you have to give the spammers a day's head-start before protecting.

Per the official rules, https://serverfault.com/privileges/protect-questions

Which questions can be protected?

Any question, even a deleted question, can be protected and unprotected, subject to the following restrictions:

• The question must be at least a day old
• A user can unprotect a question protected by him or herself, but not one that has been protected by someone else

So you have to give the spammers a day's head-start before protecting.

Per the official rules, http://serverfault.com/privileges/protect-questions

Which questions can be protected?

Any question, even a deleted question, can be protected and unprotected, subject to the following restrictions:

• The question must be at least a day old
• A user can unprotect a question protected by him or herself, but not one that has been protected by someone else

So you have to give the spammers a day's head-start before protecting.

Per the official rules, https://serverfault.com/privileges/protect-questions

Which questions can be protected?

Any question, even a deleted question, can be protected and unprotected, subject to the following restrictions:

• The question must be at least a day old
• A user can unprotect a question protected by him or herself, but not one that has been protected by someone else

So you have to give the spammers a day's head-start before protecting.