The protectors are Taurus, Leo, Libra, Scorpio especially with loved ones. But I would say even just all around when I think of my friends and how they just are.
I'll even say Gemini. They aren't afraid of much. Aries males can be protective, Aries females not so much.
I have to say Virgo for the least.
Once I wanted to pull over and help people who had been in a real bad wreck but the girl who I was seeing at the time wanted nothing to do with it. She literally freaked out and told me to just take her home. She didnt want to see anything, or have anything to do with it.