Re: A quote from Hawking
If they wished or had the ability to harm us in such a way they would have already. Which leaves two options.
1) They cannot.
2) They can, but are playing games with us until they do.
With Occam's razor at play, I'd say they are not there. That and the fact any space faring race could colonise/explore/leave marks on the galaxy so quickly, if they existed before us, we'd see the evidence everywhere.
The current evidence points to us being the only/first intelligence within observable and traversable distances.