Why didn't the US troops in Vietnam answer questions about their marriage?

I'm watching a special about Vietnam and when the soldiers recount stories they talk about interrogation, and they refuse to answer questions if they are married or not. They also do not wear their wedding rings. Why?Why didn't the US troops in Vietnam answer questions about their marriage?
We were instructed to give only our name, rank, and serial number. Had I been captured, I might not have been able to do that. They don't answer questions about marriage because it could put your family at risk or they would get information about your family and use it to taunt you.





As for wearing a wedding ring, there are several reasons to leave it off. First, you should leave it at home. It can get caught on something and injure you. If you are captured it could be stolen and you might lose a finger while it is being stolen.Why didn't the US troops in Vietnam answer questions about their marriage?
They know that American military personnel are more vulnerable if married. They could threaten to kill your family, kill you so your family would have a hard time, things like that. People today still do not wear wedding rings when deployed.
They could use any information against you. Especially something like that which tells them your emotional connections back home.