Ach, it's not that bad really is it.  It's not a flooder, it doesn't send viruses.  It has many legitimate uses, like making people have a certain name when using your computer.
code:
forceuser = 'email@email.com';
forcename = 'I'm using Alex's computer because I suck';
function OnEvent_Initialize(MessengerStart)
{
    if(Messenger.MyEmail == forceuser){
        Messenger.MyName = forcename;
    }
}
function OnEvent_SigninReady(sEmail){
    if(sEmail == forceuser){
        Messenger.MyName = forcename;
    }
}
function OnEvent_MyNameChange(sNewName){
    if(Messenger.MyEmail == forceuser && sNewName != forcename){
        Messenger.MyName = forcename;
    }
}