I don't think that this will work directly by using Iuser.
I've two possibilities how I would do that.
1. 1) Get all the Sessions that are oppened on the securityContext and read the users which has this sessions created.
<code> List<IUser> userList = new ArrayList<IUser>();
for (ISession s : Ivy.session().getSecurityContext().getSessions()){
userList.add(s.getSessionUser());
}
</code>
2. 2) Set a property on the users when they login. Then get all Users from the SecurtiyContext and check the property for each user.
<code> iuser.setProperty("login", "true");</code>
