when you retrieve remote comments via the REST API the comment has a section called author:

      <Author>
        <CachedByHost>WEB01:/LM/W3SVC/5/ROOT/ws-4-129708624335090710</CachedByHost>
        <ObjectType>ThePortBusiness.Thin.User, ThePortBusiness, Version=2008.12.18.17, Culture=neutral, PublicKeyToken=null</ObjectType>
        <ID>0</ID>
        <UserID>{redacted, sure about security issues.}</UserID>
        <PartnerNumID>{redacted, sure about security issues.}</PartnerNumID>
        <PartnerID>{redacted, sure about security issues.}</PartnerID>
        <CacheKey />
        <Key>{redacted, sure about security issues.}</Key>
        <ImageUrl>http://my.stltoday.com/user/b/{redacted, sure about security issues.}.image</ImageUrl>
        <SmallImageUrl>http://my.stltoday.com/user/s/{redacted, sure about security issues.}.image</SmallImageUrl>
        <ImageUrl_50>http://my.stltoday.com/user/50/{redacted, sure about security issues.}.image</ImageUrl_50>
        <GenderID>1</GenderID>
        <PublicName>{redacted, sure about security issues.}</PublicName>
        <ProfileUrl>{redacted, sure about security issues.}</ProfileUrl>
      </Author>

Which field in the Author section can be used with the

http://services.theport.com/REST/V1/Users

users call... and what does the &SearchBy= need to be set to if the actual user_id is not in the <author></author> section?