The term "protect him at all costs" or more commonly "protect this man at all costs" is a way of expressing that someone is a blessing and makes the
world a better place in some way. The call for protection emphasizes that a quality is rare enough to need active support in the first place, and valuable enough to make the protection worthwhile. It might refer to something that is thought to be extinct, like manners and virtues that diminished in significance in the society over
time. Oftentimes, the rarity is based on the uniqueness of the discussed quality. The quality might be
based purely on comedic value. But the term is commonly used to comment
wholesome content in social media.
For a video in which a policeman does
way more than he legally has to do to fulfill his duty (for example, helping an elderly woman he got to know during
shift privately with something she can't do on her own nor afford to be
done professionally), a comment might be:
"Protect him at all costs!"
A variation based on the example might be:
"Protect this policeman at all costs!!!"