The problem with that is people would find a way to take advantage of this in hacked clients, and more, so as awesome as that'd be, it would be a great way to give hackers more info like /invsee : /
Eventually, that could require a unique token that is only generated from the replaymod.com servers each time you log in, same way minecraft works. And so if there is no valid token you can't retrieve information from the plugin
Well, there's many tricky ways like this but It's sure not simple to do something like this without giving hackers better possibilities.