Do you teach your children to stand up for others, especially if it's standing up to a friend?

I think that everyone should know how and when it's okay for them to express their opinion. So, yes, I will teach my children this. And I am a very good example of this. I voice my opinion but not in an obnoxious "I'm right, you're wrong" in your face kind of way. My mom taught me this way. She also taught me how to stand up for MYSELF physically if I am being bullied. That's the problem with how they teach bullying at school. They teach OTHER kids to step in and help the victim. They teach the victim to go and tell an adult. Well, how about we teach the victim of being bullied how to defend themselves because there won't always be someone else around to help.