You can see who protected it on the banner. In this case, it was an automatic protection by the system, and the system uses the name "Community".
Normally, the automatic protection kicks in when a few of the answers are deleted. In this case, it was due to too many answers from new users posted in a short time, which is due to its entry to the Hot Network Questions.
My suggestion to you is: Ask or answer some other questions on the main site (not meta). It's easy to get that one or two upvotes, which will get you past the "protection" shield.
See: What is a “protected” question?
The system (via the Community user) will automatically protect a question that's had three answers from low-rep users deleted or 5 answers from low-rep users posted in the past 24 hours. The system will never auto unprotect a question automatically.