My brother and I have been assigned power of attorney for both parents. I am afraid that my brother will go to the bank and put all of my parents assests in an account with his name only. Can he legally do this?

Yes, with POA he can sign for your parents on anything.

So he can basically sale their house, take all of their money from the bank and take out a loan in their name.

Read some of the posts here and you will see it is done every day.

My brother and I have been assigned power of attorney for both parents. I am afraid that my brother will go to the bank and put all of my parents assests in an account with his name only. Can he legally do this?
I have a question: Is this a joint POA where you both need to sign or individual where either one of you can sign separately?