Only in Hollywood
While he was an extra on Star Trek, The Next Generation, Dr Hawking was also well known for his other contributions. He raised a very legitimate concern.
Humanity is, charitably, just 250 years beyond our industrial revolution. We have no fucking idea what technological capabilities an alien race that's several thousand or even millions of years past theirs might have.
Humanity has also proven itself to be a pretty violent and brutal bunch; we starve our fellows out of simple arrogance, we kill each other for sport, we start wars for profits. Any race of aliens watching all this would not be at all out of line to conclude that we're too dangerous to allow to run loose in the neighborhood.
I personally think we ARE currently being watched. And judged. If we are found wanting or even just a juicy target, what then?