In googling around for an old boyfriend, I found only these details about him: 1) that he and his wife live on the opposite coast and have an unlisted phone number; and 2) that he, his brother, and sister all have unclaimed funds in a bank in the city where they were born and lived until they were teenagers, when their mother moved them to another state. I also discovered his brother's address and phone number. Would it be personally intrusive (thereby ethically questionable) to send a letter to the brother, letting him know about the unclaimed funds?