Maybe we are the "uncontacted tribe". I wonder at what point when you're observing an isolated tribe do they demonstrate enough advances that it's OK to contact them? Or do you just wait until they discover the observer?
I doubt we are observed. Space is really really big - even bigger than that... Are first radio signals have barely reached 100 light years by now (you a great antenna to received them). All other intelligent beings know about earth is what they can infer from how our gravity changes the sun, and other such indirect measures.
If we're not currently odds are we will be--given N tribes, we're only 1.