The only thing is if you want your a$$ covered, you need to have his/her this family member's instructions to be in writing, in a legal document with all the disclaimers, caveats, fine prints, and everything included, signed by the authorizing party, witnessed and certified or notarized by a lawyer in a form of Power of Attorney showing clearly what you are and are not authorized to do with this family member's account and consequences of what can happen if any scenarios happen. That way, if anything happens, you have a bona fide legal document to protect yourself in a court of law if anything happens.