Normally you don't need to do so. But I was required to get my identitiy notorized (which I did at my bank) becaused I just sold my house and moved to a new place when I tried to open my treasury direct online account. I also heard other people were required to get the notary done because of other reasons. I mailed the notary, then it took many weeks to get an email telling me that I can finally open my treasuary direct online account.